JPS61105882A - Laser irradiating device - Google Patents

Abstract

PURPOSE:To prevent the light-transmission of the laser beam uniformizing means of a laser irradiating device from being lowered and to prevent the laser beam uniformizing means from being broken down due to an adhesion of burning substances, which occurs along with an irradiation of laser emitted light, and at the same time, to enable to efficiently perform a laser irradiation by a method wherein the laser irradiating device is provided with a projection irradiating means, the laser beam uniformizing means and a masking means, which is disposed between the laser beam uniformizing means and a surface to be irradiated. CONSTITUTION:This laser irradiating device is constituted of a homogeneous light irradiating rod 5 with its end surface 5a, from where a laser emitted light having the flattened intensity distribution is outputted, a projection irradiating means 6 consisting of a lens 6a, which is disposed at the prescribed distance in the front of the end surface 5a of this homogeneous light irradiating rod 5, and a masking plate 7, which is disposed in close contact to the end surface 5a of the homogeneous light irradiating rod 5. According to such a constitution, a laser emitted light, which is outputted from the end surface 5a of the homogeneous light irradiating rod 5 through the masking plate 7, is converged by the lens 6a and is projected on the focal length (f) of the lens 6a. As a result, an irradiation surface 8 having a uniform intensity distribution, and at the same time, having the desired configuration is formed.

Description

Detailed Description of the Invention [Technical Field of the Invention 1] The present invention relates to a laser beam homogenizing means (device for uniformly irradiating a laser beam over a specific range (hereinafter referred to as "uniform light irradiation rod")). This relates to the laser irradiation device used.

[Technical costs of the invention and its problems] Laser beams are usually narrow, high-energy-density lights with a Gaussian distribution, and this property can be used to cut and thermally process machined objects, or to use them as laser scalpels. An incision is being made in the human body.

However, when treating a birthmark on the human body, for example, it is difficult to cauterize cells or capillaries of the birthmark on the surface layer of the skin uniformly over a wide area using a laser beam having a Gaussian distribution.

For this reason, for example, a device that uniformly irradiates a laser beam over a specific range of the human body (for example, JP-A-58-839
No. 73) has been proposed.

As shown in FIG. 7, this device includes a laser generator 1,
A lens 2 that converts the laser beam emitted from the laser generator 1 into a parallel beam or a focused beam, and an indirect light guide path (a combination of optical fiber or reflecting mirror) 3 that guides the laser beam that has passed through the lens 2. , indirect light guide path 3
It has a lens 4 that refocuses the laser beam from the lens 4, and a uniform light irradiation rod 5 disposed approximately at the focal point of this lens 4, and flattens the laser beam from the output side of the uniform light irradiation rod 5. It is designed to output a laser beam that is

FIG. 8(a) shows the intensity distribution of the input light to the uniform light irradiation rod 5, and FIG. 8(b) shows the intensity distribution of the output light. (a) and (1)) are both orthogonal X,
The intensity distribution of the laser beam on the Y axis (in mm) is expressed as
It is expressed in dB in the direction perpendicular to the Y-axis (two-axis direction).

The input light having the non-uniform intensity distribution shown in the figure <a) is
By passing through the uniform light irradiation rod 5,
It is converted into flattened output light as shown in 1).

When such a device is used to treat a birthmark, it is disclosed in, for example, Japanese Patent Application Laid-open No. 148959/1983 that a mask means formed in the shape of the birthmark is used. In this method, a thin plate cut out in the shape of a birthmark is placed between the uniform light irradiation rod 5 and the irradiated surface, and these three
Unless the uniform light irradiation rod, the mask means, and the object to be irradiated are arranged closely to each other, the effect of the mask means will not be exhibited.

This means that the laser light emitted from the uniform light irradiation rod 5 is diffused to a greater degree than that of a general optical fiber.
This is because the etched portion of the mask means becomes blurred. Therefore, when laser light is emitted for nevus treatment, the cauterized skin vaporizes or scatters, causing the uniform light irradiation rod 5
It adheres to the @ surface and eventually leads to destruction of the end surface. This drawback is not limited to the medical field, but also occurs in the machining field. Further, in this method, since the uniform light irradiation rod is brought into close contact with the end face and abuts on the irradiated surface, the laser beam having the size of the mask means is directly irradiated. Therefore, if the irradiation area is to be increased, the uniform light irradiation rod itself must be made larger.

Another method is T EA (T ranceverse
There is a method using a laser (excitedatmosphere). This is due to C generated in the so-called TEA mode, which avoids discharging in a direction perpendicular to the traveling direction of the laser beam.
It uses O2 laser light. Since the TEACO2 laser having a wavelength of 10.6 μm emits a thick beam of 1 q with a diameter of icm or more, a marking mask is placed in the middle of this beam to mark the object to be irradiated.

In this case, since the CO2 laser light (infrared light) has a long focal length, it is difficult to enlarge or reduce the light using a general glass lens, and this also requires a full-sized mask.

Also, although a relatively uniform output distribution can be obtained, it is not completely flat as in the case of a uniform light irradiation rod, and the light distribution is shifted.Furthermore, the TFA laser itself is large and expensive.

[Object of the Invention] The present invention was made in view of the above circumstances, and an object of the present invention is to provide a laser irradiation device that does not destroy the laser irradiation device (and has a simple configuration).

[Summary of the Invention] In order to achieve the above-mentioned object, the present invention includes a laser beam homogenizing means for outputting a laser output beam having a flattened intensity distribution from an end face, and a laser beam uniformizing means for outputting a laser output beam having a flattened intensity distribution, and a The apparatus is characterized by comprising a projection irradiation means for projecting irradiation onto an irradiation surface, and a marking mask means disposed between the laser light equalization means and the irradiation surface. be.

[Embodiments of the invention] Hereinafter, the configuration of an embodiment of the present invention will be described in detail.

FIG. 1 shows a first embodiment of the present invention, and this laser irradiation device includes a uniform light irradiation rod 5 that outputs laser output light having a flattened intensity distribution from an end surface 5a;
It is composed of a projection irradiation means 6 consisting of a lens 6 arranged at a predetermined distance in front of the end surface 5a of the uniform light irradiation rod 5, and a mask plate 7 closely arranged on the end surface 5a of the uniform light irradiation rod 5. has been done.

Note that the mask plates 1 to 7 are preferably made of high melting point materials that are not melted by laser light. For example, molybdenum, tungsten, stainless steel lead, etc. can be considered.

At this time, when the light from the uniform light irradiation rod 5 is enlarged or reduced by the lens 6a, the relationship with the focal length of the lens 6a is as follows.

Uniform light irradiation [As shown in Fig. 6, the distance between the end face and the center of the lens 6a is a, the focal length of the lens 6a is f, and the image magnification is n, then a-[(n + 1)/n] f On the other hand, if the frontage angle is θ, the -) U of the uniform light irradiation rod 5 is A (square), and the distance from the center to the end surface when projected onto the lens 6a is L, then L = E7A/2+a
tan θ−8 to Fl+[(n +1 ＞/n ]
f tan 0 Generally, the lens diameter is less than the focal length 1 ([)<f 2 ). Therefore, 1<f/2;, A/Fl+ [(n + 1 > /n] f
tan θ〈f/2 A=3. n=3.3. θ-7.56°, f = 25
Then, L=3/U+ [(3,3+1 ＞/3.3ko・25t
an 7.56°-2,12+4.32=6.44 On the other hand, f/2=25/2=1 2. 5,°, 6.44<12.5 Therefore, combinations of these values are possible. Furthermore, lens 6
If the light is incident on the entire surface of the size a, the light will be distorted, so we will use the entire surface of the lens 6a. Just do it.

That is, about (-<f/4).

However, in the above numerical value, A=5. If n = 2, L = 5/F7 + 3/2-25 tan7.56° = 3
．． 54. +4.98=8.5 Compared with the lens diameter, L>f/3, and the enlarged and projected image has barrel distortion.

Considering the above, when the light emitted from the uniform light irradiation rod 5 reaches the lens 6a and is focused and formed as an enlarged or reduced image on the opposite side, the light emitted from the uniform light irradiation rod 5 It is necessary to determine the dimensions and position of the uniform light irradiation rod 5 so that the uniform light irradiation rod 5 and the lens 6a are located at a position where the distance does not extend beyond 2/3 of the focal length f of the lens 6a.

Fig. 2 shows an example in which the apparatus shown in Fig. 1 is applied to a gas laser processing machine.
A laser tube 20 having a diameter of M, an L-shaped laser beam guide tube 22 fixed to the output end of the laser tube 20 and having a reflection mirror 21 at a corner, and a A diffuser lens '27'I that diffuses the diffused laser beam 23, a uniform light irradiation rod 25 that receives the diffused laser beam from this diffuser lens 24, and a uniform light irradiation rod 25 that is arranged on the output surface of this uniform light irradiation rod 25 and can be replaced with one of various shapes. Each groove structure is fixed to the possible mask plate 1 26 and a lens 28 disposed after it and focusing on the workpiece 27.The laser tube 20 is equipped with a gas pump 29 and a cooling device necessary for its operation. A device 30 and an excitation power supply 31 are connected.The workpiece 27 is placed on a processing table 32 and processed.The uniform light irradiation rod 25 and the mask plate 26 are It is constructed with appropriate means such as a lead screw so as to move up and down in the direction of arrow X as necessary, and can be enlarged or reduced.

As described above, according to the laser irradiation device having the structure in which the mask plate 7 is disposed on the end surface 5a of the uniform light irradiation rod 5, the uniform light emitted from the end surface 5a of the uniform light irradiation rod 5 through the mask plate 7 is The laser output light, which has an intensity distribution and has a shape determined by the mask plate 7, is focused by a lens 6a, which is a projection means, and is projected onto a specific position determined by the focal length f of this lens 6a. , an irradiation section 8 having a uniform intensity distribution and a desired shape.
is formed. Therefore, IC or other machining can be performed without directly contacting the end surface 5a of the uniform light irradiation rod 5 with the surface of the workpiece, and in this case, the burnt material of the workpiece may be It does not adhere to the lens 6a, which is the projection irradiation means 6.

FIG. 3 particularly shows the configuration when applied to the medical field. Among these, those having the same functions as those shown in FIG. 1 are designated by the same reference numerals.

This laser irradiation device includes a uniform light irradiation rod 5, a projection irradiation means 6A consisting of a lens 6a and a holder 9, and a mask plate 7 that is removably arranged in close contact with an end surface 5a of the uniform light irradiation rod 5. It consists of

The holder 9 is formed into a cylindrical shape, and houses a uniform light illuminator 5 at one end and a lens 6a at an intermediate position, and has a rectangular illumination hole 10 bored at the other end. A light #J made of a material that is also transparent (for example, transparent)
It has an end surface portion 11.

The distance between this irradiation end surface portion 11 and the lens 6a is
Focal length of a is 1! fif and the distance between the lens 6a and the end surface 5a of the uniform light irradiation rod 5. Further, an insertion hole 9a for inserting the mask plate 7 is formed in the holder 9 where the end surface 5a of the uniform light irradiation rod 5 is located, and the mask plate 7 is formed to be detachable. In this case, the mask plate 7 can be secured using various suitable fixing means, such as using friction with the opening 9a.

Further, a transparent plate 12 is disposed on the side surface of this holder 9 over a range from the lens 6a to the irradiation end face portion 11, and the inside of the holder 9 can be observed from the outside through this transparent plate 12. is now possible.

According to the laser irradiation device configured as described above, the laser output light outputted from the end face 5a of the uniform light irradiation rod 5 is converged by the lens 6a via the mask hole of the mask plate 7, and externally from the irradiation hole 10 of the irradiation end face portion 11. is irradiated.

Therefore, by irradiating the laser output light with the irradiation end face part 11 in contact with the skin surface, it is possible to efficiently treat bruises, etc. In this case, the skin surface is Since it is visible, it is possible to clearly recognize the parts that have already been irradiated with the laser output light of the irradiation end face part 11 and the parts that will be irradiated from now on. can do.

Furthermore, mask plates of various shapes are prepared and can be selected and inserted as appropriate depending on the required shape. Furthermore, since the lens 6a and the uniform light irradiation rod 5 are housed in the holder 9 at a predetermined distance ^1t from the irradiation end face 11, the burnt substances on the skin are absorbed by the lens 6.
a or the end portion 5a of the uniform light irradiation rod 5.

FIG. 4 is also particularly effective for medical use, and shows the irradiation surface 7J shown in FIG. Marks 13 are placed on the inner surface of the irradiation hole 10A and are located on the upper and lower sides and on the left and right sides of the irradiation hole 10A, respectively.

When a laser irradiation device is constructed using the holder 9 having such an irradiation end surface 11A, this irradiation end surface 1
1A is brought into contact with the skin surface to irradiate laser output light, it is possible to treat bruises and the like using the marks 13 above and below or on the left and right sides of the irradiation hole 10A as landmarks.

FIG. 5 shows a third embodiment of the present invention.
Components having the same functions as those shown in the figures are denoted by the same reference numerals, and detailed explanation thereof will be omitted.

The laser irradiation device shown in this figure is different from the one shown in FIG. A rod-shaped body 15 drilled through the rod-shaped body 15, and an irradiation end face portion 10B supported by the tip of the rod-shaped body 15 and having an irradiation hole 9B bored therein.
This is how the holder 8B is constructed.

Similarly to the laser irradiation device having the above configuration, it is possible to efficiently irradiate laser output light through the mask plate 7 without visually recognizing bruises, etc. on the skin surface, and to remove burnt substances from the lens 6a and the like. End surface 5a of uniform light irradiation rod 5
It will not stick to the surface.

The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the invention.

For example, although the function of enlarging/reducing the projection irradiation means has been disclosed only for FIG. It can also be implemented as a configuration that can be replaced with other items.

In this way, the enlargement or reduction can be selected or adjusted appropriately depending on the size of the object to be irradiated, so it is possible to irradiate extremely efficiently with a uniform light irradiation unit of a single size. Of course, it is necessary to satisfy the condition L<f/2 so that 1q.

Furthermore, in FIGS. 3 to 5, not only a part of the holder but also the entire holder may be made of a transparent material.

Alternatively, a transparent plate may not be particularly used for visual recognition, and one or more holes may be simply formed.

Furthermore, the position of the mask plate 1 is set to the illumination OA end face 1 on the side of the irradiated object unless the function of enlarging/reducing is particularly required.
It can be carried out even if "1" is placed on the 1 side.

[Effects of the Invention] According to the present invention described in detail above, it is possible to prevent a decrease in light transmittance or damage to the laser beam uniformizing means due to adhesion of burnt substances due to irradiation of the laser cutting edge, and to improve efficiency by the mask means. A laser irradiation device that enables good laser irradiation can be provided.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a first embodiment of the invention, Fig. 2 is a plan view showing a second embodiment of the invention, and Fig. 3 is a perspective view showing a third embodiment of the invention. , FIG. 4 is a plan view showing the illumination OA end face portion of the laser irradiation device shown in FIG. 3, FIG. 5 is a perspective view showing the fourth embodiment of the present invention, and FIG. 7 is a perspective view showing a conventional laser beam irradiation device, and FIGS. 8(a) and (b) are laser input/output for uniform light irradiation in the device shown in FIG. 7. This is a graph that does not show the intensity distribution of light. 5.25... Uniform light irradiation Rondo, 6.6A, 6
B... Projection irradiation means, 6a, 28...
Lens, 7.26...Mask plate, 8...
Irradiation surface, 9.9B... Holder, 10.10△, 10B... Irradiation hole, 11.11
A, 11B... Irradiation end face portion, 12...
Transparent plate, 13... Mark, 14... Cylindrical body, 15... Rod-shaped body. Representative Patent Attorney Noriyuki Chika (and 1 other person) -17=

Claims (1)

[Claims] a laser beam homogenizing means for outputting laser output light having a flattened intensity distribution from an end face; a projection irradiation means for projecting and irradiating the laser output light onto a surface to be irradiated; the laser beam homogenizing means and the irradiated surface; 1. A laser irradiation device characterized by comprising: a mask means for marking arranged between the surface and the surface.