JP2007171286A - Linear light radiation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a linear light radiation device capable of freely changing a divergence angle of linear light. <P>SOLUTION: A columnar lens 20 for converting a laser light flux emitted from a laser light source 10 to a linear light flux and a cylindrical lens 20 for converging or diffusing the linear light flux emitted from the columnar lens 20 are disposed on an optical axis of the laser light flux emitted from the laser light source 10, and a lens moving means is provided which moves the cylindrical lens 30 in a direction of an optical axis and comprises a linear guide device 40 and a ball screw device 50. Since a divergence angle of linear light passing the cylindrical lens 30 is changed in accordance with a distance between the columnar lens 20 and the cylindrical lens 30, the cylindrical lens 30 is moved in the direction of the optical axis by using the lens moving means, whereby linear light having a proper spread angle according to a distance to an object to be irradiated can be obtained. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a linear light irradiation apparatus that irradiates an irradiation object with linear (one-dimensional) light.

  Conventionally, in the measurement field, the cutting field, etc., a linear light irradiation apparatus that irradiates a surface with a linear light beam is used (see, for example, Patent Document 1). FIG. 5 is a perspective view in which only basic elements of such a linear light irradiation apparatus are extracted and drawn.

  A laser beam L having a beam diameter d emitted from the laser light source 11 is incident on the circumferential surface of the cylindrical lens 21, is refracted when passing through the cylindrical lens 21, and is a surface orthogonal to the central axis C of the lens 21. It progresses while spreading like a fan. At this time, light does not spread in the extending direction of the central axis C. As a result, at a position away from the cylindrical lens 21 by a predetermined distance, a linear light flux L ′ having a line width d and a length U is obtained. In addition, in order to obtain such linear light, the lens only needs to have a cylindrical surface, and a configuration using a cylindrical concave lens as described in Patent Document 2 can also be used.

JP 2001-158003 A Japanese Patent Laid-Open No. 07-120687

  In the linear light irradiation apparatus as described above, the irradiated light beam is irradiated with the linear light flux L ′ that has passed through the cylindrical lens 21 and spread in a fan shape. The amount of light per unit length (strictly, unit area) is much lower than the amount of light per unit area of the light beam L from the laser light source 11, and sufficient light intensity (or luminance) is ensured depending on the purpose. Becomes difficult. On the other hand, when the object to be irradiated is near, the light intensity per unit length is too high, which may cause problems such as halation. Therefore, it is desirable to adjust the spread angle of the linear light so that the length U of the linear light on the irradiated surface is appropriate according to the distance to the irradiated object. However, in the above-described conventional linear light irradiation device, the spread angle of the linear light is determined by the diameter of the cylindrical lens, and therefore the spread angle of the linear light cannot be freely changed during use. .

  The present invention has been made to solve such a problem, and an object thereof is to provide a linear light irradiation apparatus capable of freely changing the spread angle of linear light.

The linear light irradiation apparatus according to the present invention, which has been made to solve the above problems, is a linear light irradiation apparatus that irradiates a linear light beam to an irradiation object.
a) a light source;
b) a first lens for converting a light beam emitted from the light source into a linear light beam;
c) a second lens that converges or diffuses the linear luminous flux emitted from the first lens according to the distance from the first lens;
d) lens moving means for changing the distance between the two lenses by moving the first lens and / or the second lens in the optical axis direction;
It is characterized by having.

  The “light source” mentioned here is not necessarily a light source that actively emits light. For example, an emission end face of an optical waveguide (such as an optical fiber) that guides emitted light from a light source provided at another location. Including all that emit light. Various light sources can be used, but a laser light source is more preferable because it can enter the lens with the light beam diameter as narrow as possible.

  The first lens may be anything as long as it can convert an incident light beam into a linear light beam, and the second lens transmits a linear light beam emitted from the first lens to the first lens. As long as it can be converged or diffused according to the distance from the linear light irradiation apparatus according to the present invention, as shown in FIG. It is desirable to use the cylindrical lens 101 as the second lens and the cylindrical lens 102 as the second lens. 4B and 4C, both the first lens and the second lens may be either a cylindrical lens 102 or a cylindrical lens 101.

  The “cylindrical lens” in the present invention is a lens having an incident surface and an output surface that are cylindrical surfaces, and includes not only a lens having a cylindrical body shape but also a cylindrical concave lens. The “cylindrical lens” refers to a lens whose incident surface is a flat cylindrical surface and whose output surface is a convex or concave cylindrical surface. When these lenses are used as the first lens, they play a role of converting a light beam emitted from a light source into a linear light beam, and when used as the second lens, It plays a role of further diffusing the linear light that spreads in a fan shape and converges the linear light to make it parallel light or converge light.

  In the linear light irradiation device of the present invention having the above-described configuration, the linear light beam emitted from the first lens is refracted when passing through the second lens. At this time, the first lens and the second lens are refracted. The linear light is converged or diffused according to the distance between and the spread angle changes. Therefore, by changing the position of the first lens and / or the second lens on the optical axis by the lens moving means, linear light having an appropriate spread angle according to the distance to the irradiated object and the irradiation purpose is obtained. be able to.

  Hereinafter, the best mode for carrying out the present invention will be described based on examples. The linear light irradiation apparatus of the present embodiment includes a laser light source 10, a cylindrical lens 20, a cylindrical lens 30, and a lens moving mechanism for moving the cylindrical lens 30 (FIG. 1). The cylindrical lens 20 is a lens having a substantially circular cross section in which the entrance surface and the exit surface are convex cylindrical surfaces, and the cylindrical lens 30 has a plane entrance surface and an exit surface composed of a convex cylinder surface. This is a saddle-shaped lens. The cylindrical lens 30 and the cylindrical lens 20 are arranged in parallel to each other so that the plane side of the cylindrical lens 30 faces the cylindrical lens 20. Further, the laser light source 10 is arranged so that the optical axis of the emitted light beam is orthogonal to the axial direction of each lens.

  The lens moving mechanism includes a long guide rail 41, a linear guide device 40 including a slider 42 sliding on the guide rail 41, and a ball screw device 50 for driving the slider 42. The guide rail 41 of the linear guide device 40 is disposed along the optical axis of the laser light emitted from the laser light source, and the cylindrical lens 30 is fixed to the upper surface of the slider 42. The ball screw device 50 includes a rotating shaft 51 having a spiral thread groove on the peripheral surface, a moving element 52 screwed to the rotating shaft 51, and a motor 53 that rotationally drives the rotating shaft 51. The moving element 52 is connected to the slider 42 of the linear guide device 40 by a connecting member 60. Therefore, according to such a lens moving mechanism, the rotating shaft 51 is rotated by the motor 53, whereby the moving element 52 is moved along the rotating shaft 51, and accordingly, the cylindrical lens 30 on the slider 42 is moved to the light. It can be moved in the axial direction.

  In the linear light irradiation apparatus of the present embodiment having the above-described configuration, the laser light beam emitted from the laser light source 10 enters the cylindrical lens 20 and is refracted when passing through the cylindrical lens 20; In the plane perpendicular to the central axis, it is diffused in a fan shape to become linear light. The linear light beam emitted from the cylindrical lens 20 is incident from the plane side of the cylindrical lens 30 and is emitted from the cylindrical surface side.

  At this time, the spread angle of the linear luminous flux emitted from the cylindrical lens 30 changes according to the distance between the cylindrical lens 20 and the cylindrical lens 30. For example, when the cylindrical lens 20 and the cylindrical lens 30 are separated from each other by a predetermined distance X, the linear light that spreads out in a fan shape from the cylindrical lens 20 and is converged by the cylindrical lens 30. When the light becomes parallel light (FIG. 2A) and the distance X ′ between the two lenses becomes longer than X, the linear light is further converged and emitted as concentrated light (FIG. 2B). On the other hand, when the distance X ″ between the two lenses is shorter than the X, the linear light emitted from the cylindrical lens 20 in a fan shape is further diffused by the cylindrical lens 30 (FIG. 2C). It should be noted that the length U of linear light when parallel light can be determined by a combination of the diameters of the cylindrical lens 20 and the cylindrical lens 30 (FIG. 3).

  Therefore, according to the linear light irradiation apparatus of the present embodiment, by moving the cylindrical lens 30 in the optical axis direction by the lens driving mechanism described above, the spread angle of the linear light emitted toward the irradiation object is increased. Can be easily adjusted. Further, by selectively using linear light and spot light by controlling the divergence angle, energy concentration and diffusion can be freely performed.

  The linear light irradiation apparatus as in the present embodiment can be used in various apparatuses. For example, by scanning a linear laser beam in a direction perpendicular to the linear laser beam using a polygon mirror or the like, a planar area is obtained. Can be used for a measuring device or the like that performs three-dimensional measurement in the region.

  Note that the above embodiment is merely an example of the present invention, and it is obvious that changes and modifications can be made as appropriate within the scope of the present invention. For example, in the above-described embodiment, an example is shown in which the spread angle of the linear light is adjusted by moving the cylindrical lens that is the second lens, but in addition to that, the first lens or the first lens and the second lens are adjusted. It can also be set as the structure which moves both. Further, the lens moving means may be one that allows the user to manually move the lens in addition to the one that moves the lens using a driving source such as a motor as in the above-described embodiment.

The schematic plan view which shows the state which looked at the principal part structure of the linear light irradiation apparatus which concerns on one Example of this invention from the top. It is principle explanatory drawing of the linear light irradiation apparatus which concerns on the Example, Comprising: (a) is when collimating linear light, (b) is when converging linear light, (c) Indicates a case where linear light is diffused. It is a figure which shows the change of the length of parallel light by the combination of the lens diameter of the linear light irradiation apparatus which concerns on the Example, Comprising: (a) is a case where a cylindrical body lens with a large diameter is used, (b) is The case where a cylindrical lens with a small diameter is used is shown. It is a schematic plan view which shows the example of the combination of the 1st lens which concerns on the linear light irradiation apparatus of this invention, and a 2nd lens, Comprising: (a) is an example which combined the cylindrical lens and the cylindrical lens, (b) is a cylindrical. The example which combined the lens and the cylindrical lens is shown, (c) shows the example which combined the cylindrical lens and the cylindrical lens. The perspective view which shows schematic structure of the conventional linear light irradiation apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 11 ... Laser light source 20, 21 ... Cylindrical lens 30 ... Cylindrical lens 40 ... Linear guide apparatus 41 ... Guide rail 42 ... Slider 50 ... Ball screw apparatus 51 ... Rotary shaft 52 ... Mover 53 ... Motor 60 ... Connecting member

Claims (4)

In the linear light irradiation device that irradiates the irradiated object with a linear light beam,
a) a light source;
b) a first lens for converting a light beam emitted from the light source into a linear light beam;
c) a second lens that converges or diffuses the linear luminous flux emitted from the first lens according to the distance from the first lens;
d) lens moving means for changing the distance between the two lenses by moving the first lens and / or the second lens in the optical axis direction;
The linear light irradiation apparatus characterized by having.   The linear light irradiation apparatus according to claim 1, wherein the first lens is a cylindrical lens, and the second lens is a cylindrical lens.   The linear light irradiation apparatus according to claim 1, wherein each of the first lens and the second lens is a cylindrical lens. The linear light irradiation apparatus according to claim 1, wherein each of the first lens and the second lens is a cylindrical lens.

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