JP5862129B2 - Laser ignition igniter - Google Patents

Description

  The present invention relates to a laser ignition type igniter that ignites an igniting agent using laser light, and relates to a laser ignition type igniter including a safety device.

2. Description of the Related Art Conventionally, an igniter that ignites an igniting agent by causing a current to flow through a platinum wire or a resistor to generate heat is used for ignition of explosive pyrotechnics such as a rocket motor and an igniter for a gas generator.
In recent years, various laser ignition igniters using laser light have been proposed in order to ignite more reliably, and further, laser ignition igniters equipped with various safety devices have been proposed. .
For example, in the prior art described in Patent Document 1, a direction control device configured to be rotatable and capable of reflecting laser light for ignition in various directions, and laser oscillation capable of emitting laser light toward the direction control device And a single or a plurality of optical fibers having a light receiving surface directed toward the direction control device. And the safe arm apparatus for laser ignition pyrotechnics which reflects and transmits a laser beam toward the selected optical fiber by controlling a direction control apparatus is disclosed.
In the prior art described in Patent Document 2, two optical fiber connector ferrules that accommodate optical fibers and are provided with lenses on the end faces of the optical fibers are prepared so as to face each other on both sides of the sleeve and at a predetermined interval. The tip of the optical fiber connector ferrule is provided and fixed in the sleeve. Then, a laser insertion hole is drilled in the sleeve portion between the tip of one optical fiber connector ferrule and the tip of the other optical fiber connector ferrule, and the shutter member is inserted into and removed from the shutter insertion hole. A safe arm device for laser ignition pyrotechnics capable of transmitting and blocking light is disclosed.
In addition, in the prior art described in Patent Document 3, a detonator for a detonation-controlled ammunition that can be exploded at a desired time or a desired position using a MEMS (Micro Electro Mechanical Systems) shutter is disclosed. Has been.

JP 2006-118443 A Japanese Patent Laid-Open No. 08-303300 Japanese Patent No. 4652831

In the prior art described in Patent Document 1, the direction control device that reflects laser light has a reflecting mirror and a rotation drive unit, and the device becomes larger. In addition, a guide, a stopper, and the like that can position the reflection angle of the direction control device with high accuracy are required, and the size of the device increases.
Further, in the prior art described in Patent Document 2, since it is necessary to mechanically insert and remove the shutter member, a driving device such as a motor for inserting and removing the shutter member is necessary, and the size is increased.
Further, the conventional technique described in Patent Document 3 uses a MEMS shutter and is relatively expensive.
The present invention has been made in view of such a point, and an object of the present invention is to provide a laser ignition type igniter that is smaller in size, lower in price, and safer.

In order to solve the above problems, the laser ignition type igniter according to the present invention takes the following means.
According to a first aspect of the present invention, a laser oscillation device that generates laser light having polarization, a collimator lens that is a lens that converts the laser light into parallel light, and the laser light converted into parallel light are collected. A condensing lens that is a light-emitting lens, an ignition agent disposed in the vicinity of the focal point of the focused laser beam, and a shutter member that can control transmission and blocking of the laser beam having polarization This is a laser ignition type ignition device accommodated in the inside.
The collimating lens and the condensing lens are both substantially spherical ball lenses, and the shutter member is disposed between the collimating lens and the condensing lens, and the laser is applied when no voltage is applied. When a voltage is applied while blocking light, the polarizing plate and a liquid crystal plate are configured to transmit the laser beam, and the liquid crystal plate has a polarization direction with respect to the polarizing plate when no voltage is applied. Is an electric liquid crystal shutter that is set so that the polarization direction coincides with that of the polarizing plate when a voltage is applied, and the laser oscillation device does not go through an optical fiber, and the collimating lens It is a laser ignition type igniter accommodated in the said case in the state which contacted.
According to a second aspect of the present invention, there is provided a laser oscillation device that generates laser light having polarization, a collimator lens that is a lens that converts the laser light into parallel light, and the laser light converted into parallel light. A condensing lens that is a lens that condenses the light, an igniting agent disposed in the vicinity of the focal point of the collected laser light, a shutter member that can control transmission and blocking of the laser light having polarization, Is a laser ignition type igniter accommodated in the case.
The shutter member is disposed between the collimating lens and the condensing lens so as to block the laser beam when no voltage is applied and to transmit the laser beam when a voltage is applied. The polarizing plate is composed of a liquid crystal plate, and the liquid crystal plate rotates 90 degrees with respect to the polarizing plate when no voltage is applied, and the polarizing direction coincides with the polarizing plate when a voltage is applied. The laser oscillation device is housed in the case in contact with the collimating lens without passing through an optical fiber.
The collimating lens is a substantially spherical ball lens, and the condensing lens has a spherical surface on the side of the collimating lens, and the side opposite to the collimating lens is orthogonal to the optical axis of the laser beam. This is a laser ignition type igniter in which an igniter side plane that is a plane to be formed is formed.

According to the first and second aspects of the invention, a laser oscillation device that generates polarized laser light is built in, and the generated laser light is condensed at a focal position using a collimator lens and a condenser lens. Thus, the energy density is increased, and the igniting agent is disposed at the light collecting position.
Thereby, for example, a more compact, inexpensive, and integrated laser ignition type igniter that can be reliably ignited even when a laser oscillation device having a relatively low output is used can be configured.
Also, a safer laser ignition type igniter can be realized by providing a shutter member capable of controlling the blocking and transmission of the laser beam in the path from the laser oscillation device to the ignition agent.

  According to the first and second inventions, since the shutter member is disposed at the position where the energy density of the laser beam is the lowest (the position where the beam diameter of the laser beam is the largest), the energy when the laser beam is transmitted Loss can be suppressed, and burning of the shutter member when the laser beam is blocked can be prevented.

Further, according to the first and second inventions, a relatively inexpensive laser ignition that can be further reduced in size by using an inexpensive spherical ball lens having a relatively short focal length. Type igniter can be realized.
In addition, the ball lens only has to be arranged on the optical axis of the laser beam, and it is not necessary to be aware of the inclination of the optical axis of the lens.

  Further, according to the second invention, the thickness of the condensing lens in the optical axis direction can be made thinner by using the condensing lens having a larger refractive index, so that the laser ignition type igniter can be made smaller. Can be.

  Next, a third invention of the present invention is the laser ignition type igniter according to the second invention, wherein the laser beam can be transmitted between the igniter side plane and the igniter. A laser-ignited igniter in which a flat plate-shaped transmitting member that is substantially flat is disposed.

  According to the third aspect of the invention, the use of the flat plate-like transmission member is convenient because the focal length of the condensing lens can be adjusted.

Next, when the laser ignition type igniter described in the present embodiment includes the flat plate-shaped transmission member, the ignition agent is on the optical axis of the laser beam and faces the ignition agent. It is disposed at a position in contact with the surface of the flat plate-shaped transmitting member, and the focal position of the laser beam is on the optical axis of the laser beam and in the vicinity of the surface of the ignition agent on the flat plate-shaped transmitting member side. Thus, the condensing lens and the flat plate-shaped transmission member are configured.
Further, when the flat plate-shaped transmission member is not provided, the igniting agent is disposed at a position on the optical axis of the laser light and in contact with the surface of the condenser lens facing the igniting agent, A laser ignition type igniter in which the condensing lens is configured such that a vicinity of a surface of the igniting agent on the condensing lens side is a focal position of the laser light on the optical axis of the laser light It is.

In the laser ignition type igniter described in the present embodiment, the igniting agent is disposed at a position in contact with the condenser lens or the flat plate-shaped transmission member, and therefore, the positioning position of the igniting agent is easy.
In addition, since the igniting agent can be loaded not on the spherical surface but on the flat surface, the igniting agent can be easily loaded. Furthermore, when the igniting agent is loaded while being compressed, the igniting agent can be easily made uniform in pressure because it is loaded on a flat surface instead of a spherical surface.

Next, when the laser ignition type igniter described in the present embodiment includes the flat plate-shaped transmission member, the ignition agent is on the optical axis of the laser beam and faces the ignition agent. Is disposed at a position a predetermined distance away from the surface of the flat plate-shaped transmitting member along the optical axis, and is on the optical axis of the laser beam and on the surface of the ignition material on the side of the flat plate-shaped transmitting member. The condensing lens and the flat plate-shaped transmission member are configured so that the vicinity is a focal position, and the laser beam can be transmitted between the flat plate-shaped transmission member and the ignition agent and has heat insulation properties. It is filled with a heat insulating transmission member.
Further, when the flat plate-shaped transmission member is not provided, the igniting agent is along the optical axis from the surface of the condensing lens that is on the optical axis of the laser beam and faces the igniting agent. The condensing lens is disposed at a position separated by a predetermined distance, and the condensing lens is on the optical axis of the laser light so that the vicinity of the surface of the condensing lens on the condensing lens side is the focal position of the laser light. A laser ignition type igniter that is configured and is filled with a heat transmissive member having heat insulation properties and capable of transmitting the laser light between the condenser lens and the ignition agent.

  In the laser ignition type igniter described in the present embodiment, the focal position of the condensing lens is set at a position away from the condensing lens (or the flat plate-shaped transmitting member), so that the energy of the condensed laser light is It is possible to prevent the conductive lens or the plate-like transmitting member from being lowered. In addition, by filling the gap between the condensing lens and the igniting agent with a heat-insulating and transmitting member that transmits laser light and has heat insulating properties, the laser ignition type that suppresses the energy loss of the laser light and also facilitates positioning of the igniting agent. An igniter can be realized.

(A) is a perspective view explaining each member which comprises the laser ignition type igniter 1 which incorporated the laser diode 20, (B) is a laser beam LB with the laser ignition type igniter 1 which assembled | attached each member. It is sectional drawing cut | disconnected along the optical axis ZL. It is a figure explaining the example of the structure of the collimating lens 31, the condensing lens 32, and the shutter member 70 which condenses the laser beam LB radiate | emitted from the laser diode 20 to the ignition agent 42, and the ignition agent 42 and the condensing lens 32 ( Or it is a figure explaining the example which has arrange | positioned the ignition powder 42 so that the flat transmission member 33) may contact. It is a figure explaining the example of the structure of the collimating lens 31, the condensing lens 32, and the shutter member 70 which condenses the laser beam LB radiate | emitted from the laser diode 20 to the ignition agent 42, and the ignition agent 42 and the condensing lens 32 ( Or it is a figure explaining the example by which the predetermined distance D2 between flat transmission member 33) is filled with the heat insulation transmission member 41 (filled). It is a figure explaining the example of the structure of the collimating lens 31, the condensing lens 32, and the shutter member 70 which condenses the laser beam LB radiate | emitted from the laser diode 20 to the ignition agent 42, and the ignition agent 42 and the condensing lens 32 ( Or it is a figure explaining the example in which the space of the predetermined distance D2 is formed between the flat transmission member 33). It is a figure explaining the example of the structure of the collimating lens 31, the condensing lens 32, and the shutter member 70 which condenses the laser beam LB radiate | emitted from the laser diode 20 to the ignition agent 42, and the ignition agent 42 and the condensing lens 32 ( Or it is a figure explaining the example by which the predetermined distance D2 between flat transmission member 33) is filled with the heat insulation transmission member 41 (filled).

EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated using drawing.
● [Overall configuration of laser ignition type igniter 1 incorporating laser diode 20 (FIG. 1)]
First, the overall configuration of an embodiment of the laser ignition type igniter 1 will be described with reference to FIGS. The example shown in FIGS. 1A and 1B shows an example in which a laser diode 20 that generates laser light having polarization is built.
The laser ignition type igniter 1 includes a diode holder 61, a laser diode 20 (corresponding to a laser oscillation device), a collimator lens 31, a shutter member 70, a condensing lens 32, a spacer 11, a heat insulating transmission member 41, an ignition agent 42, and an ignition agent. A holder 62, main charge 50, cap 63, and the like are housed in the case 10. The laser diode 20 is accommodated at one end (the left end portion in FIG. 1) in the case 10, and the collimating lens 31, the shutter member 70, and the light condensing on the optical axis ZL that is the axis of the laser light output window of the laser diode 20. The lens 32 and the ignition powder 42 are accommodated.
Moreover, as shown in the example of FIG. 2 described later, the heat insulating transmission member 41 may be omitted.

The laser diode 20 emits a laser beam LB from the light emitting unit Fs when power is supplied to the terminal 20A. In the present embodiment, a laser diode 20 that emits a laser beam LB having polarization is used. The optical axis of the emitted laser beam LB is indicated by the optical axis ZL. The laser diode 20 is held in the case 10 by a diode holder 61.
Since the emitted laser beam LB has a predetermined divergence angle and spreads in a conical shape, it is collected near the surface of the igniting agent 42 using the lens group 30 including the collimating lens 31 and the condenser lens 32. Lighted.
The collimating lens 31 converts the laser light LB emitted from the laser diode 20 into parallel light. In the example shown in FIGS. 1A and 1B, the collimating lens 31 is a substantially spherical ball lens, and is set so that the distance to the light emitting portion Fs of the laser diode 20 substantially matches the focal length f1. .
The condensing lens 32 condenses the laser beam LB converted into parallel light toward a condensing position Fg that is an intersection between the vicinity of the surface of the ignition agent 42 and the optical axis ZL. In the example shown in FIGS. 1A and 1B, the condensing lens 32 is a substantially spherical ball lens, and is set so that the distance to the condensing position Fg substantially coincides with the focal length f2.

The shutter member 70 is, for example, an electric liquid crystal shutter. A power source is connected to the terminal 70A, and transmission and blocking of the laser beam LB having polarization can be controlled. The shutter member 70 is arranged, for example, so that the direction is adjusted so that the laser beam LB is blocked when not energized and the laser beam LB is transmitted when energized. As the shutter member 70, for example, one having a general structure in which a polarizing plate is bonded to a liquid crystal plate whose polarization plane can be controlled by a voltage is used. In this case, the liquid crystal plate is set so that the polarization direction coincides with the polarizing plate when a voltage is applied, and is set so that the polarization direction rotates 90 degrees with respect to the polarizing plate when no voltage is applied. ing. In addition, by using the laser diode 20 that emits the laser beam LB having polarization, two shutter members whose polarization directions are orthogonal to each other are not required, and the laser beam LB can be transmitted through one shutter member 70. Blocking is controlled and high transmittance is secured.
In the example of FIG. 1, a shutter member 70 is disposed between the collimating lens 31 and the condenser lens 32. Since the laser beam LB is parallel light between the collimating lens 31 and the condensing lens 32, the interval between the collimating lens 31 and the condensing lens 32 can be arbitrarily set in order to arrange the shutter member 70. Yes, it is not necessary to consider the focal length. In addition, since the beam diameter of the laser beam LB is the largest and the energy density is the smallest between the collimating lens 31 and the condenser lens 32, the energy loss is smaller when the laser beam LB is transmitted, and when the laser beam LB is blocked. Since the burning of the shutter member 70 can be prevented, it is more preferable.
By providing the shutter member 70 as a safety device, it is possible to prevent ignition of the igniting agent 42 even when the laser beam LB is generated due to an erroneous signal (even when input from an optical fiber or the like). It is possible and can improve safety.
Further, since the shutter member 70 is a thin plate and can be controlled by a voltage, a driving device such as a motor is not required, and even if it is built in the laser ignition type igniter 1, a sufficiently small size can be realized.

The heat insulating and transmitting member 41 is a member that transmits the laser beam LB and has heat insulating properties, and serves as a spacer that fills the space between the ignition agent 42 and the condenser lens 32.
The ignition powder 42 is a powder that is directly ignited by the laser beam LB.
Further, the heat insulating and permeable member 41 and the igniting agent 42 are held in the case 10 by the igniting agent holder 62.
The main charge 50 is an explosive component that is ignited and combusted by the combustion of the igniting powder 42 and generates a quantity of heat necessary for the igniter and a large amount of hot particles and debris, and the amount is appropriately adjusted according to the necessary quantity of heat.
The case 10 is a pressure-resistant metal case, for example, and the cap 63 is made of, for example, resin or metal. Further, in the case 10, a spacer 11 having a diameter of the collimating lens 31 and an inner diameter of the diameter of the condenser lens 32 is accommodated.
The combustion products of the igniting agent 42 and the main charge 50 have a structure in which the cap 63 at the other end (right end portion in FIG. 1) of the case 10 is broken and ejected.

In the laser ignition type igniter 1, all the components except the case 10 described above are accommodated in the case 10, and it is only necessary to connect a power source to the terminal 20A of the laser diode 20 and the terminal 70A of the shutter member 70. Easy to handle.
The laser diode 20 is preferably easily available and inexpensive and has a wavelength of near infrared to visible light. Since the laser beam output requires energy for igniting the igniting agent in a short time, for example, an output having an output of 0.2 [W] or more, preferably 0.5 [W] or more is required. Even a laser diode with 0.5 [W] output has a size of about 5 to 6 [mm] and is sufficiently small. In addition, the higher the output power of the laser diode, the shorter the time from the start of laser irradiation to the ignition, for example, if it is 0.5 [W] or more, a short ignition delay time of 1 [ms] or less can be realized.

As the igniting agent 42, for example, an igniting agent used in a general igniter such as a potassium perchlorate / zirconium mixture or a potassium nitrate / boron mixture can be used. If the black component such as carbon black is included in the ignition agent in an amount of about 1 [%] to 5 [%], the absorption rate of the laser beam LB is improved, and even a laser diode having a relatively low output can be obtained. This is preferable because the ignition delay time can be further shortened.
As the main charge 50, for example, a general igniter component such as a potassium nitrate / boron mixture or a potassium perchlorate / aluminum mixture can be used.
Further, when the laser ignition type igniter 1 is used as a detonator (detonator, detonator, etc.), an igniting agent such as lead azide or DDNP (diazodinitrophenol) is used as the igniting agent 42, and the main charge. Explosive components such as pen slits and HMX (Octogen) can be used.
Further, the heat insulating and transmitting member 41 is a member having a heat insulating property as well as a member having little attenuation due to the transmission of the laser beam LB. A predetermined distance D2 is provided between the condensing lens 32 and the igniting agent 42, and the predetermined distance D2 is filled with the heat insulating transmission member 41 so that the radius, focal length, and refractive index of the condensing lens 32 can be freely designed. The degree can be improved (see (Formula 1) described later), and the positioning of the igniting agent 42 can be facilitated.
Moreover, as a material of the heat insulation transmission member 41, the transparent epoxy resin used for the sealing agent of LED other than a transparent acrylic resin, a transparent silicon resin, etc. can be used, for example.

  In the example shown in FIGS. 1A and 1B, both the collimating lens 31 and the condenser lens 32 are ball lenses. Compared with a general convex lens that is not a sphere, the ball lens has a large curvature and thus has a short focal length, and is relatively easy and inexpensive to manufacture. In addition, since it is a sphere, it is not necessary to be aware of the inclination of the lens optical axis by simply aligning the lens centers O1 and O2 with the optical axis ZL, and the optical axis can be easily adjusted. Therefore, by using the ball lens, the length of the laser ignition type igniter 1 in the direction of the optical axis ZL can be shortened and further downsized, and the assembly can be facilitated. Further, since the energy density is increased by condensing the laser light with two lenses, a small laser diode may be used, and the laser ignition type igniter 1 can be further downsized.

Next, the focal length, refractive index, and the like of the collimating lens 31 and the condenser lens 32 will be described with reference to FIG.
In the general laser diode 20, a light emitting portion distance D1 that is a distance from the light emitting portion Fs to the transmission window surface (laser diode surface) is about 1 [mm]. Therefore, when the collimating lens 31 is disposed in contact with the transmission window of the laser diode 20, a lens having a distance of 1 [mm] from the lens surface to the focal point is preferable.
Here, when the refractive index of the spherical collimating lens 31 is N1, the focal length is f1, and the lens radius is R1, the following expression is established.
Focal length f1 = refractive index N1 * lens radius R1 / [2 * (refractive index N1-1)] (Formula 1)
In this case, focal length f1 = lens radius R1 + light emitting portion distance D1 = 2 + 1 = 3 [mm].
If the focal length f1 = 3 [mm] and the lens radius R1 = 2 [mm] are substituted into the above (Equation 1), the refractive index N1 = 1.5 is calculated. It can be seen that the collimating lens 31 needs to be formed.
Note that, when the refractive index N1 <1.5, the focal length f1 increases, but if the lens radius R1 is reduced, the focal length can be made equivalent. For example, when the lens radius R1 = 1.75 [mm] is set, the focal length f1 = the lens radius R1 + the light emitting portion distance D1 = 1.75 + 1 = 2.75 [mm], and the refractive index N1≈ from (Equation 1). 1.469. In this case, since the lens radius R1 of the collimating lens 31 can be made smaller, the laser ignition type igniter 1 can be made smaller.

The condenser lens 32 is designed so that the condenser position Fg separated from the lens surface by a predetermined distance D2 is a focal point, where the refractive index of the condenser lens 32 is N2, the lens radius is R2, and the focal length is f2. For example, predetermined distance D2 = 1 [mm], lens radius R2 = 2 [mm], focal length f2 = lens radius R2 + predetermined distance D2 = 2 + 1 = 3 [mm], and these are substituted into (Equation 1), A refractive index N2 = 1.5 can be obtained. In this case, since the collimating lens 31 and the condenser lens 32 can be the same ball lens, they can be easily assembled without being confused at the time of assembling (if the diameter is the same but the refractive index is different, they are confused). Easy to misassemble).
In order to further reduce the size of the laser ignition type igniter 1, it is preferable to set the condensing position Fg closer to the surface of the condensing lens 32. For example, when the lens radius R2 = 2 [mm] and the focal length f2 = 2 [mm] so that the condensing position Fg is in contact with the lens surface (predetermined distance D2 = 0), the refractive index is obtained from (Equation 1). N2 = 2 can be obtained.
Further, for example, when the condensing position Fg is set at a position 0.2 [mm] away from the condensing lens 32 and the lens radius R2 = 1.75 [mm], the refractive index N2≈ from Equation (1). 1.815 can be obtained.

  2 and 3 to be described below are the laser ignition type igniter 1 shown in FIG. 1B, the laser diode 20, the collimating lens 31, the shutter member 70, the condensing lens 32, the igniting agent 42, the heat insulation. It is a figure explaining the example of the various structures of the collimating lens 31 which has extracted the transmissive member 41, and condenses the laser beam LB radiate | emitted from the laser diode 20 to the ignition agent 42, and the condensing lens 32. FIG. 1 to 3, the same laser diode 20 is used.

[Example 1 of configuration of collimating lens 31, condensing lens 32, and shutter member 70 that condenses laser beam LB emitted from laser diode 20 onto ignition agent 42 (FIG. 2)]
The examples shown in FIGS. 2B to 2E show an example in which the heat-insulating and transmitting member 41 is omitted and the igniting agent 42 is disposed at a position in contact with the condenser lens 32 (or the flat plate-shaped transmitting member 33). Yes. Since it is sufficient to fill the igniting agent 42 so as to be in contact with the surface of the condenser lens 32 (or the flat plate-shaped transmission member 33), fine adjustment of the loading position of the igniting agent 42 is unnecessary, and positioning of the igniting agent 42 is easy. is there.

2B to 2E, the collimating lens 31 is a ball lens, which is the same as that shown in the example of FIG. Therefore, in the description of the example of FIGS. 2B to 2E, the condenser lens 32 will be described.
The example of FIG. 2B shows an example in which the condensing lens 32 is a ball lens and the igniting agent 42 is disposed at a position in contact with the condensing lens 32. In the example of FIG. 2B, when the focal length f22 of the condenser lens 32 = the radius R2 of the condenser lens 32 and the radius R2 = 2 [mm], A refractive index N2 = 2 is obtained.

In the example of FIG. 2C, the condensing lens 32 has a spherical surface on the side of the collimating lens 31, and the side opposite to the collimating lens 31 (side facing the ignition powder 42) is a plane orthogonal to the optical axis ZL. That is, the igniter side plane M1 is formed. In the example of FIG. 2C, when the focal length f23 = 1.75 [mm] and the radius R2 = 2 [mm], since the incident surface is a spherical surface and the focal position is the lens surface, (Equation 1) is applied. This is possible, and the refractive index N2 = 2.3 of the condenser lens 32 is obtained. In this case, since the place where the igniting agent 42 is loaded is not a spherical surface but a flat surface, the loading operation of the igniting agent 42 is facilitated.
In this case, since the igniter side plane M1 is located inside the radius R2 of the condenser lens 32, a refractive index N2> 2 (preferably 2.1 to 2 is preferable) in order to focus on the surface of the igniter 42. It is necessary to form the condenser lens 32 with a material of about. In addition, since the thickness of the condensing lens 32 in an optical axis direction can be made thinner using the condensing lens 32 which has a larger refractive index, a laser ignition type igniter can be reduced in size.

  In the example of FIG. 2D, the condensing lens 32 has a spherical surface on the side of the collimating lens 31, and the side opposite to the collimating lens 31 (side facing the ignition powder 42) is a plane orthogonal to the optical axis ZL. Is formed, and the condensing lens 32 and the igniting agent 42 are filled with a flat plate-shaped transmitting member 33 that transmits the laser beam LB and has a flat plate shape. For example, by setting the refractive index N2 of the condenser lens 32 and the refractive index N3 of the flat plate-shaped transmission member 33 to the same refractive index, the focal length f24 can be extended by the thickness L3 of the flat plate-shaped transmission member 33. it can. In the example of FIG. 2D, when the focal length f24 = 2 [mm] and the radius R2 = 2 [mm], the refractive index N2 = 2 of the condenser lens 32 is set with reference to (Equation 1) and the like. can get. In addition, since the place where the igniting agent 42 is loaded is a plane (the igniting agent side plane M2 of the flat plate-shaped transmission member 33), the loading operation is easy. Further, if the radius of the bottom surface of the cylindrical flat plate transmission member 33 is the same as the radius R2 of the spherical surface portion of the condensing lens 32, the inclination of the optical axis of the condensing lens 32 housed in the case 10 (and the flat plate transmission). The inclination of the optical axis of the member 33 can be suppressed.

In the example of FIG. 2 (E), the igniter side plane M1 in the condenser lens 32 is a surface passing through the lens center O2 of the condenser lens 32, and is a cylindrical flat plate shape as compared with the example of FIG. 2 (D). The radius of the bottom surface of the transmissive member 33 is the same as the radius R2 of the spherical portion of the condenser lens 32. In the example of FIG. 2E, when the refractive index N2 of the condenser lens 32 = the refractive index N3 of the flat plate-shaped transmission member 33, the focal length f25 = 2 [mm], and the radius R2 = 2 [mm], With reference to 1), the refractive index N2 = 2 of the condenser lens 32 is obtained. Moreover, since the loading location of the ignition powder 42 is flat, the loading operation is easy. In addition, as compared with the example of FIG. 2D, the thickness D3 of the flat plate-shaped transmission member 33 is thicker, so that the condensing lens 32 is better accommodated in the case 10, and the inclination of the optical axis is further suppressed. be able to.
In this case, if the refractive indexes N2 and N3 of the half-ball condensing lens 32 and the flat plate-shaped transmission member 33 are both set to refractive index = 2, the thickness D3 of the flat plate-shaped transmission member 33 = the lens radius R2 = 2 [ mm].

[Example 3 of configuration of collimating lens 31, condensing lens 32, and shutter member 70 that condenses laser light LB emitted from laser diode 20 onto ignition agent 42 (FIG. 3)]
The example shown in FIGS. 3B to 3E shows an example in which a space of a predetermined distance D <b> 2 provided between the condenser lens 32 and the igniting agent 42 is filled with the heat insulating transmission member 41. The heat-insulating and transmitting member 41 is a member that is less attenuated due to the transmission of the laser beam LB and has a heat insulating property. Thereby, while being able to reduce energy loss, positioning at the time of loading the igniting agent 42 is easy. The predetermined distance D2 may be formed by the igniter holder 62 shown in FIG. The predetermined distance D2 is set as appropriate.

In each of the examples shown in FIGS. 3B to 3E, the predetermined distance D <b> 2 is filled with the heat insulating transmission member 41. In addition, it is also possible to use a crystalline transparent explosive having transparency of the laser beam LB, a transparent acrylic resin, or the like for the heat insulating and transmitting member 41. When using a transparent explosive, the energy at the time of ignition is used. Can be made larger.
In addition, the refractive index N4 of the heat insulating transmission member 41 affects the focal lengths f2A to f2E.
Further, the example shown in FIG. 3B is the same as the configuration of the laser ignition type igniter 1 shown in FIGS. 1A and 1B.

As described above, between the laser diode 20 and the igniting agent 42, the collimating lens 31 and the condensing lens 32, or the collimating lens 31, the condensing lens 32 and the flat plate-shaped transmission member 33, or the collimating lens 31 and the concentrating lens 31. The optical lens 32 and the heat insulating transmission member 41 or the collimating lens 31, the condensing lens 32, the flat plate transmission member 33, and the heat insulating transmission member 41 are used. As a result, the laser beam LB can be focused on the igniting agent 42 to increase the energy density and can be ignited. Therefore, the laser diode 20 having a relatively low output can be used and the laser beam LB can be configured at a lower price. Further, by appropriately setting the lens radius, the refractive index, and the lens shape, the size can be further reduced, and the loading of the igniting agent 42 can be facilitated.
Further, the safety can be further improved by providing the shutter member 70 in the laser beam path.

The laser ignition type igniter 1 of the present invention is not limited to the appearance, structure, configuration, shape, etc. described in the present embodiment, and various modifications, additions, and deletions are possible without departing from the scope of the present invention. It is.
Further, the laser ignition type igniter 1 described in the present embodiment can be used for various purposes in addition to the rocket motor and the igniter for the gas generator.
The numerical values used in the description of the present embodiment are examples, and are not limited to these numerical values.
Further, the above (≧), the following (≦), the greater (>), the less (<), etc. may or may not include an equal sign.

DESCRIPTION OF SYMBOLS 1 Laser ignition type igniter 10 Case 11 Spacer 20 Laser diode 30 Lens group 31 Collimating lens 32 Condensing lens 33 Flat plate transmission member 41 Heat insulation transmission member 42 Ignition agent 50 Main charge 61 Diode holder 62 Ignition agent holder 63 Cap 70 Shutter Member D1 Light emitting part distance D2 Predetermined distance Fs Light emitting part Fg Condensing position LB Laser light O1, O2 Lens center R1, R2 Lens radius f1, f2 Focal length ZL Optical axis

Claims (3)

A laser oscillation device that generates laser light having polarization;
A collimating lens which is a lens for converting the laser light into parallel light;
A condensing lens that is a lens that condenses the laser light converted into parallel light;
An igniter disposed in the vicinity of the focal point of the focused laser beam;
A shutter member capable of controlling transmission and blocking of the laser light having polarization ;
Is a laser ignition type igniter housed in a case ,
The collimating lens and the condenser lens are both substantially spherical ball lenses,
The shutter member is disposed between the collimating lens and the condenser lens;
When no voltage is applied, the laser beam is shut off,
When a voltage is applied, it is composed of a polarizing plate and a liquid crystal plate so as to transmit the laser beam.
The liquid crystal plate is an electric liquid crystal whose polarization direction is rotated by 90 degrees with respect to the polarizing plate when no voltage is applied, and is aligned with the polarizing direction when a voltage is applied. A shutter,
The laser oscillation device is accommodated in the case in contact with the collimating lens without going through an optical fiber,
Laser ignition igniter. A laser oscillation device that generates laser light having polarization;
A collimating lens which is a lens for converting the laser light into parallel light;
A condensing lens that is a lens that condenses the laser light converted into parallel light;
An igniter disposed in the vicinity of the focal point of the focused laser beam;
A shutter member capable of controlling transmission and blocking of the laser light having polarization;
Is a laser ignition type igniter housed in a case,
The shutter member is disposed between the collimating lens and the condenser lens;
When no voltage is applied, the laser beam is shut off,
When a voltage is applied, it is composed of a polarizing plate and a liquid crystal plate so as to transmit the laser beam.
The liquid crystal plate is an electric liquid crystal whose polarization direction is rotated by 90 degrees with respect to the polarizing plate when no voltage is applied, and is aligned with the polarizing direction when a voltage is applied. A shutter,
The laser oscillation device is accommodated in the case in contact with the collimating lens without an optical fiber,
The collimating lens is a substantially spherical ball lens,
The condensing lens has a spherical surface on the side of the collimating lens, and a side opposite to the collimating lens is formed with an igniting agent side plane which is a plane orthogonal to the optical axis of the laser beam.
Laser ignition igniter. The laser ignition type igniter according to claim 2 ,
Between the igniting agent side plane and the igniting agent, a flat plate-like transmission member that is capable of transmitting the laser light and is substantially flat is disposed.
Laser ignition igniter.

Images