JP4933277B2 - Lens fixing method and lens unit - Google Patents

Description

  The present invention relates to a lens fixing method and a lens unit.

  A lens used in an optical device is generally fixedly held in a “cylindrical holder” called a lens cell or a lens barrel. As one of the methods for fixing the lens to the holder, there is known “a method using laser beam welding” (Patent Documents 1, 2, etc.).

  The method of fixing the lens to the holder using laser beam welding is the problem of the fixing method by adhesion, which is a problem of the fixing method by adhesion, and the problem of the fixing method by the heat caulking Heat is transmitted to a wide range other than the above, and there is no fear of deforming other than the necessary portion of the lens frame, which is an excellent fixing method.

In Patent Document 1, an outer peripheral portion formed outside the effective lens surface of a lens is brought into contact with a “flange-shaped fixing portion” formed on a holder, and the fixing portion of the holder is melted by laser light, and a molten resin is obtained. The fine irregularities formed on the outer periphery of the lens are inserted into the lens to fix them.
In the case of this fixing method, since the depth direction of the minute irregularities on the outer periphery of the lens is directed to the lens optical axis direction, when the “force in the lens optical axis direction” acts on the lens fixed to the holder, The lens is easily detached from the holder due to “force in the direction of the optical axis of the lens”. That is, in the fixed state of the lens and the holder, the “resistance to pull out” with respect to the “force in the lens optical axis direction” is small.

  Patent Document 2 discloses a fixing method in which a holder and a lens made of the same material are made to be compatible with each other by laser light, and the two are welded together. Cannot be used to fix the gap between.

JP-A-2005-316044 JP 2006-11234 A

  The present invention has been made in view of the above-described circumstances. For example, when a glass lens is fixed in a cylindrical holder made of resin, both can be fixed when the lens and the holder are not compatible with each other. In addition, it is an object of the present invention to provide a lens fixing method capable of realizing fixing having a strong “resistance to pull out” against “force in the lens optical axis direction” and to provide a lens unit manufactured by this fixing method.

The lens fixing method of the present invention is a “method of fixing a resin lens in a cylindrical holder formed of a resin that is not compatible with the lens” and has the following features (claims) 1).
That is, the inner peripheral surface portion parallel to the lens optical axis (in the state where the lens is held) of the resin holder is used as the fixing portion, and the resin lens is held in the holder to fix the outermost edge surface of the lens. Proximity or contact with the part.

In this state, the “fixing laser beam” is condensed and irradiated on the fixing part through the lens, and the inner peripheral surface of the holder in the fixing part is melted, and the outermost peripheral cover of the lens is melted by the heat of the melted holder fixing part. Melt the surface.
Then, the melted resin of the holder is caused to enter the melted outermost peripheral edge surface of the lens to form a concavo-convex structure between the melted resins and solidify.
This increases the “resistance to pulling out” from the lens holder against the “force acting in the optical axis direction of the lens”. That is, it fixes so that the fixed lens may not be easily removed from the holder.

  The “outermost edge surface of the lens” is a portion that connects the outermost periphery of both surfaces of the lens and forms the thickness of the outermost periphery of the lens, and has a circumferential surface parallel to the optical axis or a conical surface inclined with respect to the optical axis. It is a circumferential surface.

  The inner peripheral surface forming the fixing part of the holder is parallel to the optical axis of the fixed lens, but the cross-sectional shape orthogonal to the lens optical axis is the shape of the outermost peripheral edge surface of the lens to be fixed (the lens optical axis Corresponding to the shape seen from the direction). These shapes may be circular or polygonal, and may be various shapes according to the shape of the outermost peripheral edge surface of the lens, such as an elliptical shape and a rectangular shape. Further, the cylindrical holder only needs to have the fixing portion parallel to the optical axis of the lens, and other portions other than the fixing portion may have an appropriate shape "as long as the lens can be inserted into the fixing portion".

The holder is made of resin, and the resin constituting the holder is hereinafter referred to as “holder resin”.
In the lens fixing method according to claim 1, the outermost peripheral edge surface of the lens fixed in the holder can be roughened in advance (claim 2). In this case, the holder resin melted by the irradiation of the fixing laser light is deformed so as to swell toward the outermost peripheral edge surface of the lens by heat, and enters into the minute irregularities on the rough surface of the lens outermost peripheral edge surface. Is fixed to the holder.
2. The lens fixing method according to claim 1, wherein a "concave structure" is formed in advance on the outermost peripheral edge surface of the lens fixed in the holder, and the melted holder resin enters the concave portion of the concave structure by deformation due to heat. Thus, the lens can be fixed (claim 3).

The outermost edge surface of the lens is a “concave structure or uneven structure”, and a “convex structure or uneven structure” that is loosely engaged with each other is previously “formed on the fixed part of the holder”, and both are engaged. In this state, the fixing portion can be irradiated with laser light.

That is, in a state where the “concave structure or uneven structure” on the outermost peripheral edge surface of the lens is engaged with the “convex structure or uneven structure” formed on the fixing part of the holder, the holder resin of the fixing part is melted and heated. Due to the deformation of the holder resin and the lens resin , the engagement between the two is fixed as being strong.

Oite in this case may be a "concave-convex structure formed on the outermost peripheral edge surface of the lens, and a concave-convex structure formed in the fixed part of the holder, screw structures mutually screwed together."

2. The lens fixing method according to claim 1, wherein the outermost peripheral edge surface of the lens is formed as a "tapered surface in the optical axis direction", melted at the fixing portion, and "expands toward the outermost peripheral edge surface of the lens" by heat. The lens can be fixed on the tapered surface by the holder resin deformed to ( Claim 3 ).

The lens fixing method according to claim 1, 2 or 3, as described above , the lens and the holder are “different resins that are not compatible with each other”, the fixing portion of the holder is melted, and the lens is heated by the heat of the melted holder resin. The outermost edge part of the lens is melted, and at the fixing part between the holder and the lens, the melted holder resin is allowed to enter inside the outermost edge part of the lens to form a concavo-convex structure between the melted resins and solidify. the is "solidify to form an uneven structure between the resins were melt" shall in the fixed portion of the Japanese holder and the lens.
Accordingly, since the melted resins are not compatible with each other, a “concave / convex structure” is naturally formed in a portion where both of the resins come into contact with each other due to heat deformation of each resin.

  Examples of the “combination of different resins having no compatibility” as the material of the lens and the holder include the following.

Lens holder resin
COP (cycloolefin polymer) PC (polycarbonate)
COP LCP (Liquid Crystal Polymer)
COP PBT (Polybutylene terephthalate)
COP PPS (polyphenylene sulfide)
PC LCP
PC PBT
PMMA LCP
PMMA PBT.

  In this case as well, the formation of the “concave / convex structure” can be effectively promoted by forming a concave / convex structure on the outermost peripheral edge surface of the lens and the fixing part of the holder, or by roughening the outermost peripheral edge surface of the lens. Is done. In addition, when the concavo-convex structure or the concave structure is formed, the “force from the thermally expanding holder resin” acting on the lens can be effectively reduced when the lens is fixed to the holder.

4. The lens fixing method according to claim 1, wherein the laser light reflecting surface is formed in advance as a part of the lens shape outside the effective lens surface area of the lens and irradiated from the lens optical axis direction. the laser beam, is reflected by the laser light reflecting surface, is irradiated to the fixed portion "it can (claim 4).

Further, in the lens fixing method according to any one of claims 1 to 4, "the lens fixed to the holder is incident to" outside the effective lens surface area of the incident side lens surface "where the fixing laser light is incident". As part of the shape, a refracting surface inclined with respect to the optical axis of the lens is formed, and a fixing laser beam is made incident on the lens from the refracting surface. by refracted toward the edge surface is irradiated to the fixed portion "it can (claim 5).
Since the “fixing laser beam” is focused on the fixing portion, the light energy is not concentrated on the laser beam reflecting surface and the refracting surface, and therefore the laser beam reflecting surface and the refracting surface are not melted.

The lens unit of the present invention is a lens unit formed by fixing a lens made of a material incompatible with the resin of the holder to a resin holder by the lens fixing method according to any one of claims 1 to 5. ( Claim 6 ).

As described above, in the lens fixing method of the present invention, the resin lens can be fixed to the resin holder even though the lens and the holder are incompatible materials. This fixing is performed by fixing the outermost peripheral edge surface of the lens and the “inner holder inner peripheral surface parallel to the lens optical axis” with the “ uneven structure of the lens resin and the holder resin that are not compatible ”. Even if the “force” acts on the lens, the fixing by the concavo-convex structure does not yield easily, and the “resisting resistance” to the lens holder is extremely large.

FIG. 1 is a view for explaining one embodiment of a lens fixing method according to claims 1 and 4 . In FIG. 1A, reference numeral 10 denotes a holder, reference numerals 20 and 30 denote lenses, reference numeral 40 denotes a pressing member, reference numeral 50 denotes a “light-blocking plate serving as an aperture stop”, and reference numeral ML denotes a fixing laser beam.

  The holder 10 has a cylindrical shape, and the portion indicated by reference numeral 11 in the lower end portion in the drawing is a “lens receiving portion having a light beam passage opening”, and the upper portion in the drawing in the holder 10 is for lens insertion. It is an open “lens insertion part”. The lens insertion portion is also a “laser light ML incident portion”.

  In the embodiment of FIG. 1, two lenses 20 and 30 are inserted and arranged in the holder 10, and a light shielding plate 50 serving as an aperture stop is arranged between these lenses 20 and 30. In the lens 20, one lens surface is aligned with the opening position of the lens receiving portion 11, and a portion outside the “effective lens surface area” is received by the lens receiving portion 11.

The state of FIG. 1A shows a “state where the lens 30 is fixed by laser light”. The lens optical axis direction is the vertical direction in the figure. The same applies to the following embodiments regarding the lens optical axis being in the vertical direction in the figure.

In this embodiment, the inner peripheral surface of the holder 10 forms a cylindrical surface, and the lenses 20 and 30 have a circular shape. The light shielding plate 50 is disposed between the lenses 20 and 30 and functions as an “aperture stop that shields the lens periphery”.
The lens 30 is disposed so as to overlap the lens 20 via the light shielding plate 50.
The lens 30 has an edge portion (a portion that forms part of the lens 30 but does not function as a lens) outside the “effective lens surface region” shown in the drawing. The “edge portion” of the lens 30 mainly has four “edge surface portions”. That is, the edge surface portion 31A parallel to the lens optical axis, “the edge surface portion 31B of the upper lens surface outside the effective lens surface region, and the lower lens surface outside the effective lens surface region” in FIG. And a sloped edge surface portion 32 inside the edge surface portion 31C outside the effective lens surface area of the lower lens surface.

The edge surface portion 31A parallel to the lens optical axis is the “outermost edge surface (hereinafter referred to as the outermost edge surface 31A)”, and is close to the inner periphery surface of the holder 10.
The outermost peripheral edge surfaces of both the lenses 20 and 30 form a cylindrical surface parallel to the lens optical axis. The diameter of the inner peripheral surface of the holder 10 and the diameter of the outermost peripheral edge surface of the lenses 20 and 30 are a difference of 0.01 mm. For this reason, the lenses 20 and 30 are held in the holder 10 in a state where the optical axes are aligned. The outermost peripheral edge surface of the lens 20 and the outermost peripheral edge surface 31A of the lens 30 are close to the inner peripheral surface of the holder 10 with a gap of “0.005 mm”. In this state, the outermost peripheral edge surface 31 </ b> A and the holder inner peripheral surface are substantially in sliding contact with each other, and the optical axes of the lenses 20 and 30 are automatically adjusted while being set in the holder 10.

Of course, when there is a certain difference between the inner diameter of the holder and the outer diameter of the lens, and it is necessary to align the optical axis, it goes without saying that the optical axis is aligned when the lens is set in the holder.
The holding member 40 is “cylindrical”, and as shown in FIG. 1A, the edge surface portion 31 </ b> B of the lens 30 is pressed from the upper side of the drawing, and the positional relationship of the lenses 20, 30 with respect to the holder 10 is determined. Hold in a fixed arrangement. In the example of FIG. 1, the lower end surface (bottom surface) of the pressing member 40 is planar and is in close contact with the edge surface portion 31 </ b> B.

  As described above, in this embodiment, the inner peripheral surface of the holder 10 is cylindrical, and the shapes of the lenses 20 and 30 are circular. However, the shape and shape required for the holder 10 is “cylindrical. The fixing portion that is close to or in contact with the outermost peripheral edge surface of the lens can be melted by the fixing laser beam. ”As long as such a condition is satisfied, the form and shape are free.

  In the lens 30, edge surface portions 31B and 31C, which are surface portions of the edge portion in the lens optical axis direction, are planes orthogonal to the lens optical axis, and the inclined edge surface portion 32 is conical. This sloped edge surface portion 32 is a “laser light reflecting surface”, and is therefore hereinafter referred to as a laser light reflecting surface 32.

The fixing laser beam ML is guided through the pressing member 40 and is incident in parallel to the lens optical axis from the upper lens insertion portion in the drawing. In this embodiment, the laser light ML is “a light beam having a convergence property in which a light beam cross section by a plane cross section orthogonal to the lens optical axis is a ring shape and the width of the ring is narrowed in the propagation direction”. A light beam having such a light beam shape is called “ring-shaped convergent light”. A method for generating the ring-shaped convergent light will be described later.
The material of the holder 10 is “resin that absorbs and dissolves the fixing laser beam”, and specifically, it can be colored resin such as black or “resin colored in black”. Further, a color paint that easily absorbs the fixing laser light may be “applied on the surface of a resin that transmits light of the wavelength of the laser light”.

  Among the lenses 20 and 30, at least the lens 30 is a “resin lens”. If the lens 30 is fixed to the holder 10, the lens 20 is fixedly held by the holder 10 in a “state sandwiched between the lens 30 and the lens receiving portion 11”. There is no need to fix. The lens 20 may be a resin lens or a glass lens.

  The pressing member 40 is transparent to the fixing laser beam ML. Needless to say, the lens 30 is also transparent to the laser light ML.

  In the state where the lens 20 and the lens 30 are inserted and arranged in the holder 10 as shown in FIG. 1 and suppressed by the pressing member 40, the fixing laser light ML, which is ring-shaped convergent light, is suppressed as shown in the figure. The laser light ML enters the resin lens 30 from the edge surface portion 31B of the lens 30 and is reflected and fixed by the laser light reflecting surface 32 toward the outermost peripheral edge surface 31A parallel to the lens optical axis. The part YP is irradiated. That is, the fixed portion YP is “the inner peripheral surface portion of the holder parallel to the lens optical axis”, and substantially contacts the outermost peripheral edge surface 31A.

  Since the laser light ML is “ring-shaped convergent light”, the laser light ML reflected by the laser light reflecting surface 32 is focused on the fixed portion YP in a “ring shape orthogonal to the lens optical axis”. By adjusting the positional relationship between the light ML and the holder 10, the irradiation state of the laser light ML irradiated to the fixed portion YP can be changed to a “band-like ring shape”. "Concentration state" can be adjusted.

  In the fixing part YP, the fixing laser beam ML is absorbed by the inner wall of the holder 10 to cause the holder inner wall to generate heat and melt the holder resin on the holder inner wall. At this time, the outermost peripheral edge surface 31A of the lens 30 is also melted by heat from the holder 10 side.

However, since the lens resin and the holder resin constituting the lens 30 are “not compatible”, the melted portions of the both are not integrated due to the compatibility. At this time, the holder resin melted in the fixing portion YP of the holder 10 is “deformed so as to swell” by heat, and the deformed portion 10A of the lens 30 is melted and softened as shown in FIG. The outermost peripheral edge surface is pressed and deformed so as to enter the lens 30.

  Therefore, if the irradiation of the laser beam is stopped and the melted holder resin is solidified, the state shown in FIG. 1B is fixed, and a “concave structure between the melted resins” is formed. The lens 30 is solidified on the holder 10. It was confirmed that there was no influence on the “fixed state” although slight contraction occurred at the stage where the melted portion of the holder resin and the lens was solidified.

  The step of fixing the lens 30 to the holder 10 with the laser light can be completed in a few seconds or shorter time, for example.

  As shown in FIG. 1B, when the “force F in the optical axis direction of the lens” is applied to the lens 30, the portion 10A of the holder resin “deformed so as to swell” is formed in the concavo-convex structure in the fixed portion. Since the lens enters the lens 30 in a direction orthogonal to the force F, the fixing portion exerts a strong “resisting resistance” against the force F (acts so as to extract the lens 30 from the holder 10).

  As a specific example, the diameter of the outermost peripheral edge surface 31A of the lens 30 is 10 mm, the material of the lens 30 is the aforementioned COP (trade name “ZEONEX E48R” manufactured by Zeon Corporation), and the material of the holder 10 (holder resin) When PC is polycarbonate (polycarbonate), 8 kgWt was required as the force F to extract the lens 30 from the holder 10.

  On the other hand, as shown in FIG. 1C, the “part deformed so as to swell due to heat” in the fixing portion between the lens LN and the holder HL enters the lens 30 in the same direction as the force F. When fixed, the force F required to extract the lens LN from the holder HL was 0.8 kgW. From this, it can be seen that fixing the outermost peripheral edge surface of the lens and the inner peripheral surface of the holder by the “concave / convex structure” extremely increases the “resisting resistance”.

  The modification in the said embodiment is shown below from FIG. In addition, in order to avoid complication, about a holder and a lens, also in each following drawing, like FIG. 1, the code | symbol 30 is attached | subjected with respect to a lens and the code | symbol 10 with respect to a holder.

  The embodiment of FIG. 2 is an embodiment of the lens fixing method according to claim 2 and shows the state of the fixing portion as an explanatory diagram. The outermost peripheral edge surface 30A of the lens 30 is roughened in advance as schematically shown in FIG. When the fixing portion is irradiated with laser light, the melted holder resin of the holder 10 is deformed so as to swell due to heat, and enters and is solidified into minute irregularities on the outermost peripheral edge surface of the lens 30. In the figure, reference numeral 10B indicates “a holder resin that has entered and solidified into minute irregularities on the outermost peripheral edge surface”.

  In this fixing process, the lens 30 is also melted. However, due to the roughening, heat transfer from the melted holder resin is less than that in the embodiment of FIG. In addition, the “effect of the force from the molten resin” of the holder 10 can be reduced, and a large force is not applied to the lens 30 at the time of fixing, so that the internal stress generated in the lens 30 can be reduced.

  Also in this case, when the “force F in the lens optical axis direction” acts on the lens 30, the deformed portion 10 </ b> B of the holder resin in the concavo-convex structure in the fixed portion enters the lens 30 in the “direction orthogonal to the force F”. Since it has entered, the fixing portion exerts a strong “resisting resistance” against the force F (acts so as to extract the lens 30 from the holder 10).

FIG. 3 shows two reference examples of the lens fixing method .
In these reference examples, a “concave structure” is formed in advance on the outermost peripheral edge surface of the lens 30 fixed to the holder 10.
In the example shown in FIG. 3A, the concave structure 30C has a “cross-sectional shape of a rectangular shape”, and as shown in FIG. 3B, the holder resin 10C melted and “deformed to swell” is formed into the concave structure 30C. The lens 30 is fixed to the holder 10 by entering into the inside and solidifying.
In the example shown in FIG. 3C, the concave structure 30D has a “triangular cross-sectional shape”. As shown in FIG. 3D, the holder resin 10D that has been melted and “deformed to swell” is formed into the concave structure 30D. The lens 30 is fixed to the holder 10 by entering into the inside and solidifying.

  3A and 3B and the examples shown in FIGS. 3C and 3D, when the “force F in the lens optical axis direction” is applied to the lens 30, the holder in the concave structure in the fixed portion Since the portions 10C and 10D of the resin “deformed so as to swell due to heat” enter the concave structures 30C and 30D of the lens 30 in a direction perpendicular to the force F, the fixing portion is strong against the force F. Of resistance.

In the reference example shown in FIG. 4, the concave structure formed in advance on the outermost peripheral edge surface of the lens 30 is a step 30E. As shown in FIG. 4B, the holder resin 10 </ b> E that has been melted and “deformed to swell” enters the concave portion of the step 30 </ b> E and is solidified to fix the lens 30 to the holder 10.
In the example shown in FIGS. 4A and 4B, when the “force F in the lens optical axis direction” is applied to the lens 30, the holder resin is deformed so as to swell in the concave structure (step 30E) in the fixing portion. Since the portion 10E that has entered the concave portion of the concave structure (step) 30E of the lens 30 in a direction orthogonal to the force F, the fixed portion exerts a strong “resistance to slip” against the force F.

FIG. 5 shows two other reference examples .
In these embodiments, an uneven structure is formed in advance on the outermost peripheral edge surface of the lens 30 fixed to the holder 10. In the example shown in FIG. 5A, the concavo-convex structure 30F has a rectangular wave cross-sectional shape, and as shown in FIG. 5B, the holder resin 10F that has been melted and “deformed so as to swell” is removed from the concavo-convex structure 30F. The lens 30 is fixed to the holder 10 by entering into the recess and solidifying.
In the example shown in FIG. 5C, the concave structure 30G has a sawtooth cross-sectional shape. As shown in FIG. 5D, the holder resin 10G that has been melted and "deformed to swell" is formed into a concave portion of the concave-convex structure 30G. The lens 30 is fixed to the holder 10 by entering and solidifying.

  5 (a) and 5 (b) as well as the examples shown in (c) and (d), when the “force F in the lens optical axis direction” acts on the lens 30, the holder in the concave structure in the fixed portion Since the portions 10F and 10G of the resin “deformed so as to swell” enter the concave portions of the concave-convex structures 30F and 30G of the lens 30 in a direction orthogonal to the force F, the fixing portion is strong against the force F. Demonstrate resistance.

As shown in FIG. 5C, when the outermost peripheral edge surface of the lens 30 has a concavo-convex structure 30G having a sawtooth cross section, this concavo-convex structure is formed as a “screw groove”, while the fixing portion of the holder 10 A screw thread that is loosely screwed with the screw groove is formed, and the lens 30 and the holder 10 are engaged with each other by screwing the screw groove and the screw thread, and in this state, laser light irradiation is performed to fix both. it may be so.

Of course, the cross-sectional shape of the concavo-convex structure on the outermost peripheral edge surface is not limited to the shape shown in FIG. A convex structure or a concave-convex structure that engages with a concave structure or a concave-convex structure on the outermost peripheral edge surface of the lens 30 is formed in the fixed portion of the holder 10, and the laser beam is applied to the fixed portion in a state in which both are engaged. Of course, irradiation can be performed ( claim 2 ).
FIG. 6 shows another reference example .
The outermost peripheral edge surface of the lens 30 is formed as a tapered surface 30H inclined in the optical axis direction. In the fixed portion, the holder resin 10H melted and “deformed so as to swell” is caused to abut against the tapered surface 30H. Then, the lens 10 is fixed. Also in this case, when “the force F in the lens optical axis direction” is applied to the lens 30, the engagement between the tapered surface 30 </ b> H in the fixed portion and the portion 10 </ b> H of the holder resin “deformed to swell” is applied to the force F. On the other hand, since a drag force is generated, the fixing portion exhibits a strong “resisting resistance” against the force F.

In the case of the reference examples shown in FIGS. 3 to 6, the “force acting on the lens 30” is small from the holder resin that melts and “deforms to swell” when the holder 10 is melted at the time of fixing. Since no large force is applied to the lens 30, the internal stress generated in the lens 30 can be reduced.

When the outermost peripheral edge surface is roughened as in the reference examples shown in FIGS. 2 to 6 or a concave structure or a concavo-convex structure is formed, even if the lens 30 itself does not melt, it melts and “swells”. Since the holder resin that has been deformed ”enters the concave portion of the rough surface with the minute irregularities or the concave portion of the concave structure / concave structure, the fixing is performed. Can be fixed.

  As in the embodiment shown in FIG. 1A, a laser beam reflecting surface 32 is formed in advance as part of the lens shape of the lens 30, and the fixing laser beam ML irradiated from the lens optical axis direction. Is reflected by the laser light reflecting surface ML and irradiated to the fixed part YP, the condensing state of the laser light irradiated to the fixed part YP by making the cross-sectional shape of the laser light reflecting surface ML convex or concave Can also be adjusted. The “laser light reflecting surface formed as a part of the lens shape” is not limited to the laser light reflecting surface 32 in FIG.

  For example, in the embodiment shown in FIG. 7, the lens 30 is fixed to the holder 10 in a state where the lens 20 and the lens 30 are held by the holding member 40 with respect to the holder 10. The “upper lens surface in FIG. 30” in FIG.

  In this embodiment, the fixing laser light ML, which is ring-shaped convergent light, is incident with an inclination with respect to the lens optical axis as shown in FIG. The lens 30 is fixed to the holder 10 by being refracted in a direction away from the optical axis and “totally reflected” at the flat edge portion 31C in contact with the light-shielding plate 50 and condensed at the fixed portion YP.

  In this embodiment, the edge surface portion 31C is a “laser light reflecting surface”. Since the laser beam ML is “totally reflected inside the lens” by the edge portion 31C, the laser beam ML is not affected by the laser beam ML.

  In the lens fixing method of the present invention, the fixing laser beam ML is irradiated to the fixing portion YP through the lens 30. As in the example described above, the laser beam ML is reflected by the laser beam reflecting surface in the lens. Instead of reflecting and irradiating the fixed part YP, it is also possible to irradiate the fixed part YP “directly through the lens”.

FIG. 8 is a diagram showing an embodiment in such a case.
In this embodiment, a refracting surface 31D inclined with respect to the lens optical axis is formed as a part of the lens shape outside the effective lens surface region of the lens 30 on the incident side lens surface of the fixing laser light ML. In the lens fixing method, the laser beam ML is incident on the lens 30 and the fixing laser beam is refracted toward the outermost peripheral edge surface 31A by the refracting surface 31D to irradiate and fix the fixing portion YP. ( Claim 5 ).

  Although not shown in FIG. 8, when the lens 30 is fixed to the holder 10, the lens 30 is outside the effective lens surface area on the laser light incident side (for example, a planar shape orthogonal to the lens optical axis outside the refractive surface 31 </ b> D). Needless to say, the portion) can be held down and fixed by the cylindrical pressing member 40 shown in FIGS.

In the embodiment as shown in FIG. 8, the laser ML focused on the fixed portion YP is not orthogonal to the outermost peripheral edge surface 31A but has an inclination with respect to the outermost peripheral edge surface 31A. In order to effectively concentrate the energy of the fixing laser beam ML as the melting energy on the fixed portion YP, it is preferable that “the inclination angle is as small as possible (close to orthogonal)” with respect to the outermost peripheral edge surface portion 31A. As the incident angle of the laser beam ML to the fixed portion YP is inclined with respect to the outermost peripheral edge surface portion 31A, the reflection component at the outermost peripheral edge surface portion 31A increases, and the energy used for fixing decreases, and the reflection is reduced. The fixed laser beam ML may enter the light shielding plate 50 and damage the light shielding plate 50.

  For this reason, it is preferable that the laser beam ML is incident on the outermost peripheral edge surface portion 31A as close to orthogonal as possible. However, in the embodiment of FIG. 8, the inclination of the laser beam ML with respect to the lens optical axis increases, and a reflecting mirror or the like is required to generate such a convergent laser beam.

One embodiment in such a case is shown in FIG.
The embodiment shown in FIG. 9 is a modification of the example shown in FIG.
That is, as shown in FIG. 9, the lens 30 is aligned with the “refractive surface 31D inclined with respect to the lens optical axis” formed as a part of the lens shape outside the effective lens surface area of the lens surface on the laser light incident side. Thus, the light emission surface 43D of the pressing member 43 is formed, and when the lens 30 is suppressed, the light emission surface 43D and the refractive surface 31D slide.

  The inner circumferential surface of the pressing member 43 is a tapered reflecting surface 43A that is inclined in the lens optical axis direction, and reflects the laser light ML that is ring-shaped convergent light so that the inclination with respect to the lens optical axis is increased. In this way, the laser light ML guided through the pressing member 43 and internally reflected by the tapered reflecting surface 43A is smoothly incident on the resin lens 30 from the refracting surface 31D and irradiated to the fixing portion YP. Is done. As in the case of FIG. 9, if the laser light ML is orthogonal to the refracting surface 31D and the light emitting surface 43D, the optical path of the principal ray of the laser light ML is not refracted by the refracting surface 31D.

The lens unit according to claim 6 can be obtained by fixing the lens 30 to the holder 10 according to each of the embodiments described above .

Finally, an example of an apparatus in which the fixing laser light is “ring-shaped convergent light” will be described.
In FIG. 10, symbols LD1, LD2,... LDN indicate a plurality (N) of semiconductor lasers. The laser beams from the plurality of semiconductor lasers LD1 to LDN are incident on the beam combining unit 100, and are combined by the beam combining unit 100 to become coupling light CP, which enters the incident end FI of the single optical fiber F. Coupled, propagated in the optical fiber F, and emitted from the emission end FO of the optical fiber F.

Specifically, as the semiconductor lasers LD1 to LDN, high-power semiconductor lasers with a wavelength of 970 nm band can be used, and as the optical fiber F, a quartz multimode with a core diameter of φ100 μm and NA of 0.22 is used. Fiber can be used. Further, in place of the N semiconductor lasers LD1 to LDN which are independent of each other, a semiconductor laser array (for example, an array of high-power light emitting portions in the above-mentioned wavelength: 970 nm band) can be suitably used.
In FIG. 10, reference sign CL1 denotes a first collimating lens, reference sign CL2 denotes a second collimating lens, reference sign FT denotes a light beam conversion optical element, and reference sign IP denotes an imaging surface. The imaging surface IP is set at a position that matches or is close to the processing surface during optical processing.

  Although the first and second collimating lenses CL1 and CL2 are depicted as single lenses in FIG. 10, they are not limited to this, and may be composed of two or more lenses. Further, the first and second collimating lenses CL1 and CL2 may be the same (having the same focal length) or “different focal lengths”. The lens surfaces of these collimating lenses CL1 and CL2 may be spherical surfaces, but it is preferable that one or both surfaces be aspherical.

  The light beam conversion optical element FT has a flat incident surface and a conical surface on the exit surface. The minute light emitting part (exit end face) FO of the optical fiber F is located at the object-side focal position of the first collimating lens CL1 via the light beam conversion optical element FT, and is divergence emitted from the light emitting part FO. First, the light beam enters the light beam conversion optical element FT, and is converted into a hollow light beam (the cross-sectional shape of the light beam is a ring shape) about the optical axis of the collimating lenses CL1 and CL2 by the action of the element. Then, the light enters the first collimating lens CL1 and becomes a “light flux that approaches the optical axis with each other” by the action of the collimating lens CL1.

  This parallel light beam is converted into “ring-shaped convergent light” by the second collimating lens CL2, and is condensed in a ring shape on the imaging plane IP. Distance: DP is the ring diameter of the laser beam condensed in a ring shape.

  In this example, the displacement means 300 has a function of displacing the light beam conversion optical element FT and the second collimating lens CL2 in the optical axis direction with respect to the first collimating lens CL1. As the displacement means 300, a conventionally known mechanism for displacing a lens group in a zoom lens or the like can be used as appropriate.

  Needless to say, the displacement means 300 may be manually operated or electrically operated, and may be configured to “program and control displacement” by a control means such as a microcomputer (not shown). Further, the displacement of the light beam conversion optical element FT by the displacement means 300 and the displacement of the second collimating lens CL2 are performed independently.

  It should be noted that at least “the driving mechanism, the first and second collimating lenses CL1 and CL2, and the light beam conversion optical element FT” of the displacement means 300 are housed in an appropriate casing.

  When the light beam converting optical element FT is displaced so as to approach the light emitting part FO in the optical axis direction, and the light beam converting optical element FT is moved away from the first collimating lens CL1, the ring diameter: DP of the ring-shaped condensing part is Get smaller. That is, the ring diameter DP can be adjusted by adjusting the distance between the first collimating lens CL1 and the light beam converting optical element FT.

  The ring-shaped convergent light obtained in this way is guided to the lens 30 by, for example, the pressing member 40 of FIG. 1, and can be used as the fixing laser light ML.

  In addition, if the exit side surface of the light beam converting optical element is not a conical surface but a pyramidal surface or a roof-shaped surface, the fixing laser beam can be condensed on the fixing portion YP in two or more points. It is possible to irradiate a plurality of point-shaped fixing portions simultaneously or sequentially with the laser light that is condensed into two or more points. Further, for example, when the light beam conversion element FT is removed from the apparatus described in FIG. 10, “laser light focused at one point” can be obtained as the fixing laser light, and thus focused at one point. Needless to say, it is also possible to perform "fixing by sequentially irradiating a plurality of point-like fixing portions" with laser light.

It is a figure for demonstrating one Embodiment of the lens fixing method. It is a figure for demonstrating the reference example of the lens fixing method. It is a figure for demonstrating another reference example of the lens fixing method. It is a figure for demonstrating the other reference example of the lens fixing method. It is a figure for demonstrating the other reference example of the lens fixing method. It is a figure for demonstrating the other reference example of the lens fixing method. It is a figure for demonstrating the modification of a lens fixing method. It is a figure for demonstrating the modification of a lens fixing method. It is a figure for demonstrating the modification of a lens fixing method. It is a figure for demonstrating an example of the apparatus which produces | generates the laser beam for fixation.

Explanation of symbols

10 Holder
30 lenses
ML fixing laser beam YP fixing part
10A Thermal expansion part of holder resin F Force acting in the lens optical axis direction

Claims (6)

A resin lens, a method of securing compatibility with no tubular in the holder made of resin with respect to the lens,
The inner peripheral surface portion of the resin holder parallel to the optical axis of the lens is used as the fixed portion, the resin lens is held in the holder , and the outermost peripheral edge surface of the lens is brought close to or in contact with the fixed portion. ,
The fixing laser beam is condensed and irradiated through the lens onto the fixing part, the fixing part of the holder in the fixing part is melted, and the outermost edge surface of the lens is melted by the heat of the melted holder fixing part. Then, in the fixing portion, the molten resin of the holder is allowed to enter the melted outermost peripheral edge surface of the lens, and a concavo-convex structure between the melted resins is formed and solidified.
A method for fixing a lens, characterized by increasing a resistance force of the lens from coming out of a holder against a force acting in a direction of an optical axis of the lens. The lens fixing method according to claim 1,
A convex or concave structure that loosely engages with the concave structure or concave-convex structure on the outermost peripheral edge surface of the lens is formed in advance on the fixing part of the holder, and fixed to the fixing part in a state in which both are engaged. The lens fixing method characterized by performing irradiation of the laser beam . The lens fixing method according to claim 1,
The outermost peripheral edge surface of the lens is formed as a tapered surface inclined in the optical axis direction.
A holder tree that has been melted and deformed to expand toward the outermost edge of the lens by heat.
A lens fixing method, wherein the lens is fixed on the tapered surface with oil . The lens fixing method according to any one of claims 1 to 3,
A laser light reflecting surface is formed in advance as part of the lens shape outside the effective lens surface area of the lens.
The fixing laser light irradiated from the lens optical axis direction is caused to be reflected by the laser light reflecting surface.
A lens fixing method, wherein the lens is reflected and irradiated to a fixing portion. In the lens fixing method according to any one of claims 1 to 4,
Effective lens on the lens surface fixed to the holder, on the lens surface on the incident side where the fixing laser beam is incident
As a part of the lens shape, a refractive surface inclined with respect to the lens optical axis is formed outside the surface area.
The fixing laser beam is incident on the lens through the refractive surface, and the laser beam is incident on the refractive surface.
The fixed part is irradiated by refracting the light toward the outermost edge.
Lens fixing method . A lens unit formed by fixing a resin lens incompatible with a resin holder to a resin holder by the lens fixing method according to any one of claims 1 to 5 .

Images