JP2003004416A - Optical displacement sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact, light optical displacement sensor that can be manufactured at a low cost. SOLUTION: An optical unit and a circuit board are accommodated in a sensor case. The optical unit includes a light projection element, a light projection lens, a light-receiving element for retaining the light-receiving element, and a light-receiving lens holder for retaining the light-receiving lens, which are integrated via an optical base that is a molding. On the optical base, a light-projecting element retention section for positioning the light-projecting element to the optical base and determining the direction for retention, a light- projecting lens retention section for positioning the light-projecting lens to the optical base and determining the direction for retention, and a light-receiving component-mounting stage that has a marginal region that can position the light-receiving element holder and the light-receiving lens holder within a prescribed adjustment range freely and determine the direction for mounting are formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical displacement sensor for measuring a distance to an object by using a light-section method or a triangulation method and detecting displacement of the object from the measured value, and more particularly, to a small size sensor. The present invention relates to an optical displacement sensor that enables weight reduction and cost reduction.

[0002]

2. Description of the Related Art As is well known in the prior art, an optical displacement sensor of this type irradiates a light beam to an object to be detected while capturing the reflected light from an oblique angle to obtain a PSD. The light is guided to a light receiving element such as a CCD or CCD, and the distance to the object is measured based on the received light output by the light section method or the triangulation method, and the displacement of the object is detected from the measured value.

FIG. 9 shows a configuration of a conventional displacement sensor.
FIG. 10 is a diagram showing the configuration of the optical unit in the displacement sensor, respectively.

In these figures, 101 is a case, 1
02 is a window plate, 103 is an optical unit, 104 is a circuit board, 105 is an electric cord, 106 is an insulating plate, 10
7 is a cover plate, 108 is a light emitting element, 109 is a light emitting element substrate, 110 is a light emitting lens, 111 is a light emitting lens holder, 112 is a light receiving element, 113 is a light receiving element substrate, 11
Reference numeral 4 is a light receiving lens, 115 is a mounting screw, 116 is an optical base, and 117 is a mounting hole.

In FIG. 9, a sensor case 101 is a molded product using aluminum as a material, a cover plate 107 is attached to one side opening, and a window plate 102 is attached to a front opening. The emission and incidence of the projection / reception beam is performed through the window plate 102.

An optical unit 103 and a circuit board 104 are housed in the case 101. As will be described later with reference to FIG. 10, the optical unit 103 includes the light projecting element 10
8, a light projecting lens 110, a light receiving element 112, and a light receiving lens 114. Also, on the circuit board 104,
Main circuit components constituting a light emitting system circuit, a light receiving system circuit, a signal processing circuit, etc. are mounted. Incidentally, 117 is a case 101
Is an attachment hole for screwing to attach the to.

As shown in FIG. 10, the light projecting element 108
A light projecting element substrate 109 for mounting a light emitting element, a cylindrical light projecting lens holder 111 holding a light projecting lens 110, and a light receiving element 1
Light receiving element substrate 113 on which 12 is mounted, and light receiving lens 11
4 is integrally connected via an optical base 116 which is a molded product using aluminum as a material. That is, the light projecting element substrate 109 and the light receiving element substrate 113 are screwed to the back side of the optical base 116. Further, the light projecting lens holder 111 is screwed and fixed in a tunnel-shaped screw hole opened on the front surface side of the optical base 116. Similarly, the light-receiving lens 114 is also inserted into a tunnel-shaped screw hole opened on the front surface of the optical base 116 and fixed with a screw 115. In the figure, 118 is a light projecting optical axis and 119 is a light receiving optical axis. Further, in FIG. 9B, 106 is an insulating plate for insulating and separating the case 101 and the optical base 116, both of which are made of metal.

[0008]

Various problems as described below have been pointed out in such a conventional optical displacement sensor. (1) In the optical base 116, since the structure for inserting the light projecting lens 110 and the light receiving lens 114 into the tunnel-shaped screw hole is adopted as a means for positioning and determining the direction, the light projecting optical axis 118 and the light receiving lens 118 are received. Optical axis 1
The angle formed by 15 is uniquely fixed, and in order to manufacture a plurality of types of products having different distance ranges, different molds must be manufactured for each model, which leads to an increase in cost. (2) Since a metal block is adopted as the optical base 116 and a tunnel-shaped screw hole for lens positioning has to be formed inside, the overall thickness increases,
It becomes an obstacle to compactness. That is, the optical base 11
Since the thickness of 6 is large, there is no room in the thickness direction in the case 101, and accordingly, the circuit board 104 must be arranged adjacent to the side of the optical unit 103, and the entire case 101 is Upsizing. (3) In addition to the block-shaped optical base 116, since the metal is used as the material of the sensor case 101, the weight of the whole is increased. (4) Almost the entire optical unit 103 is made of metal,
In addition, since the sensor case 101 is also made of metal, in order to eliminate electrical noise from the outside, it is necessary to provide an insulating gap between them or to interpose the insulating plate 106 between them. Therefore, upsizing of the case 101 is promoted accordingly. (5) From the optical base 116 to the light projecting lens 110 and the light receiving lens 1 for adjustment during the manufacturing process or shipping process.
In order to remove 14, the projection lens holder 111 is removed by moving the screw in the reverse direction while moving it along the projection optical axis, or by removing the screw 115 of the reception lens 114 and similarly removing the reception lens 114. It is necessary to move the lens in the direction of the light-receiving optical axis to extract it, and as a result, in order to set the light-projecting lens 110 and the light-receiving lens 114 again, a new lens positioning adjustment work is required, which is troublesome. . In addition, the projection lens holder 111
And the projection lens 110 are relatively strongly coupled,
In order to polish both sides of the light projecting lens 110, it is necessary to remove or reattach it, and even in this work, the optical axis is displaced and readjustment is required. In addition, the repositioning adjustment of the light projecting element 108 and the light receiving element 112 is necessary for cleaning the surfaces thereof, which is troublesome.

The present invention has been made in view of the above-mentioned problems in the conventional optical displacement sensor, and an object thereof is to provide an optical displacement sensor which can be manufactured at low cost. It is in.

Another object of the present invention is to:
It is to provide a compact and lightweight optical displacement sensor.

Another object of the present invention is to:
An object of the present invention is to provide an optical displacement sensor that can be easily adjusted during a manufacturing process or a shipping process of a light emitting / receiving optical system component.

Other objects and effects of the present invention will be easily understood by those skilled in the art by referring to the following description of the specification.

[0013]

In the optical displacement sensor of the present invention, an optical unit and a circuit board are housed in a sensor case. The optical unit includes a light projecting element, a light projecting lens, a light receiving element holder that holds the light receiving element, and a light receiving lens holder that holds the light receiving lens, which are integrally coupled via an optical base that is a molded product. Has been done. The term "optical displacement sensor" used herein includes a device such as a distance setting type photoelectric sensor that requires focus adjustment but does not require a displacement measuring function.

On the optical base, a light projecting element holding portion for positioning and orienting and holding the light projecting element with respect to the optical base, and a light projecting lens for positioning and orienting with respect to the optical base. A light projecting lens holder for holding the light receiving element holder and a light receiving component mounting stage to which the light receiving element holder and the light receiving lens holder are attached are formed.

Positioning pins and setscrews are used as means for positioning and mounting one or both of the light receiving element holder and the light receiving lens holder on the light receiving component mounting stage.

The light receiving component mounting stage is provided with a positioning hole and a screw hole at different positions, so that the same light receiving element holder or the same light receiving lens holder can be used, but a marginal area for allowing holders with different detection distances to be arranged. Exists. Here, the term “different in detection distance” includes a case where the detection distance is twice or more, a case where the detection distance is five times or more, and the like.

Accordingly, even for a plurality of models having different distance ranges, the positions and directions of the light receiving element holder and the light receiving lens holder on the stage for freely mounting the light receiving components are adjusted to realize the corresponding light receiving optical axis. This makes it possible to prepare multiple models with one optical base.

According to such a structure, since one type of optical base can be used for a plurality of models having different distance ranges, it is not necessary to prepare a molding die for each model, which is a great advantage. Cost reduction is achieved. In other words, the light receiving element holder and the light receiving lens holder have a module structure, and by changing the positions on the optical base, it is possible to support a plurality of models.

In the preferred embodiment, the light receiving component mounting stage is parallel to the plane including the prescribed light projecting optical axis and the prescribed light receiving optical axis.

According to this structure, the relationship between the light projecting optical axis and the light receiving optical axis can be freely set only by sliding or rotating the light receiving element holder and the light receiving lens holder on the light receiving component mounting stage. can do.

In the preferred embodiment, a plurality of positioning holes and fixing screw holes are pre-drilled in the light receiving component mounting stage in order to support a plurality of models having different detection ranges. With such a configuration, it is possible to easily realize the holder arrangement according to the model required at the time of manufacturing, at the time of unofficial shipping.

In a preferred embodiment, the light projecting lens held by the light projecting lens holding portion can be attached and detached in a direction orthogonal to the light projecting optical axis while maintaining its orientation.

According to this structure, when the light projecting lens is removed from the light projecting lens holder for adjusting the light projecting lens in the product manufacturing process, the light projecting lens can be reattached after the adjustment is completed. The original positioning state and the orientation determination state can be immediately restored, and the time and effort for the adjustment work each time becomes unnecessary.

In the preferred embodiment, the light-receiving lens held by the light-receiving lens holder can be attached / detached in the direction orthogonal to the light-receiving optical axis while maintaining its orientation.

According to such a structure, similarly to the case of the above-mentioned light projecting lens, the positioning state and the direction determining state of the light receiving lens are not disturbed before and after the attachment / detachment, so that the troublesome optical axis readjustment is unnecessary. Become. That is, when such a configuration is adopted, after the light receiving lens holder is fixed to the light receiving component mounting stage on the optical base, the light receiving lens can be moved in the focusing direction to perform focusing adjustment.

In the preferred embodiment, the light-receiving element holder and the light-receiving lens holder mounted on the light-receiving component mounting stage can be attached / detached in the direction orthogonal to the light-receiving optical axis while maintaining their orientations.

According to this structure, as in the case of the above-mentioned single light-receiving lens and single light-projecting lens, the light-receiving element holder and the light-receiving lens holder are adjusted even when the holder is removed from the optical base. After the work is completed, if it is reattached to the specified position, the original positioning state can be immediately restored, and no troublesome readjustment is required.

In a preferred embodiment, the projection lens holding portion is provided with a lens holding structure capable of holding a plurality of types of projection lenses having different diameters. According to such a configuration, by changing the distance range in the manufacturing process,
Even when the diameters of the light projecting lenses are different, the light projecting lenses having the large diameter or the small diameter can be immediately replaced, and the degree of freedom of changing the optical axis is improved.

In a preferred embodiment, the lens holding structure comprises a V groove for orienting the light projecting lens and a pressing member for elastically pressing the light projecting lens against the V groove.

According to this structure, the optical axis of the light projecting lens can be directed in a predetermined direction only by placing the light projecting lens at a predetermined position, and in addition, only by releasing the pressing member, the light projecting lens can be moved. It can be easily attached and detached.

In a preferred embodiment, the light receiving lens holder is provided with a lens holding structure capable of holding a plurality of types of light receiving lenses having different diameters.

According to this structure, when a light receiving lens having a different diameter is required due to the change of the distance range during the manufacturing process, such a light receiving lens can be easily replaced with the light receiving lens holder. Can be installed.

In a preferred embodiment, the lens holding structure is composed of a V groove for orienting the light receiving lens and a pressing member for elastically pressing the light projecting lens against the V groove.

According to this structure, the light receiving lens can be easily attached and detached only by placing the light receiving lens at a predetermined position on the light receiving lens holder to correctly orient the optical axis and loosening the pressing member. It can be carried out.

In the preferred embodiment, the circuit board is arranged over the optical unit in the sensor case.

According to this structure, the sensor case can be made smaller than the case where the optical unit 103 and the circuit board 104 are arranged adjacent to each other as in the conventional example shown in FIG. You can However, such an overlapping structure can be adopted, unlike the conventional optical unit, which does not employ a structure in which a screw hole is formed in a tunnel shape inside a block-shaped body and a lens holder is screwed into the hole. Has made a big contribution. Since the optical unit of the present invention is relatively flat rather than block-shaped, the overall thickness is thin, and the space for stacking the circuit board on the upper portion can be secured by that much.

In a preferred embodiment, the material of the sensor case is plastic, and the materials of the optical base, the light receiving element holder, and the light receiving lens holder are metal.

According to this structure, the light emitting and receiving system parts can be positioned with high precision through the metal, while the sensor case is made of resin to reduce the weight.
As a whole, an optical displacement sensor that is small and lightweight and has good positioning accuracy can be realized. In that case, it goes without saying that cost reduction, reduction in size and weight, and improvement of adjustment easiness can be achieved by printing the ideas of various embodiments described above.

In the preferred embodiment, a press-fitting technique can be adopted as a means for fixing the optical unit made of metal in the sensor case made of plastic.

According to this structure, in a state where the light emitting / receiving system optical component is accurately positioned, it can be easily and accurately positioned in the plastic case, and the product having good positioning accuracy as a whole. Can be provided. Moreover, if a plastic case is used as the case, the insulation as in the case of a metal case is not required, and the optical unit and the inner wall of the case can be placed closer to each other, which allows further downsizing.

In the preferred embodiment, the optical base made of metal is supported slightly above the inner wall of the sensor case made of plastic.

According to this structure, even if the plastic sensor case is bent due to an external impact, the internal optical unit itself is less likely to receive the impact or be displaced. Therefore, it is possible to prevent the occurrence of an error signal due to the optical axis shift or the like due to the impact or the like.

Particularly in the above floating floor structure, the effect is remarkable when an analog output element such as PSD is used as the light receiving element. That is, in the case of an analog output type element, the influence due to optical axis deviation, vibration, etc. appears in the output signal as it is, and thus such a floating support structure is particularly effective.

The optical displacement sensor of the present invention viewed from another side has an optical unit and an optical substrate housed in a sensor case, and the optical unit includes a light projecting element, a light projecting lens, and a light receiving device. The element and the light-receiving lens are integrally connected via a molded optical base, and plastic is used as the material of the sensor case and metal is used as the material of the optical base. There is.

According to this structure, since plastic is used as the material of the sensor case and metal is used as the material of the optical base, the overall weight of the sensor is reduced while maintaining the positioning accuracy of the optical components. Can be achieved. Moreover, since plastic is used as the material of the sensor case, it is not necessary to consider noise intrusion from inside the case, and it is not necessary to interpose an insulating material between the case inner wall and the optical base. Therefore, the entire product can be made compact by that much. In addition, since plastic is used as the material of the sensor case, press-fitting technology can be used as a means for positioning and mounting the optical unit in the sensor case, which can reduce the cost and the number of assembly steps. You can also

In the preferred embodiment, the circuit board is arranged over the optical unit in the sensor case.

With such a structure, an extra space is not required on the side of the optical unit as compared with the conventional adjacent structure, and the outer shape of the product can be made compact.

In the preferred embodiment, the optical base made of metal is supported slightly above the inner wall of the sensor case made of plastic.

According to this structure, as described above, when an external impact is applied to the sensor case, the optical parts may bend or vibrate, and an error signal may be output. Can be prevented.

At this time, if the light receiving element included in the optical unit is an analog output type element such as PSD, as described above, it is more effective for stabilizing the output signal and improving the measurement accuracy. .

In the preferred embodiment, a press-fitting technique can be adopted as a means for fixing the optical unit made of metal in the sensor case made of plastic.

According to such a configuration, as described above, even when an external impact is applied to the case and the side surface of the case is bent, the influence is unlikely to exert on the internal optical unit. Therefore, it is possible to reduce the occurrence of error signals due to optical axis deviation and vibration of optical components as much as possible.

[0053]

BEST MODE FOR CARRYING OUT THE INVENTION Various features of an optical displacement sensor according to a preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

An exploded perspective view showing the internal structure of the displacement sensor of the present invention is shown in FIG. As shown in the figure, this optical displacement sensor is configured by accommodating an optical unit 2 and a circuit board 3 in a sensor case 1 and screwing a cover plate 4 to the case 1. In the figure, 5 is a window plate fitted in the front surface of the case 1, and 6 is a mounting hole for mounting the case 1 to the support portion.

The case 1 is a molded product using plastic as a material, and is significantly lighter than a conventional product using metal as a material. The cover plate 4 is also a molded product made of plastic.

The optical unit 2 includes a light projecting element 21, a light projecting lens 10, and a light receiving element 2 as described later in detail.
It includes a light receiving element holder 28 for holding 7 and a light receiving lens holder 29 for holding the light receiving lens 12, which are integrally coupled via the optical base 7 which is a molded product.

The circuit board 3 is mounted with circuit components corresponding to various circuits required to realize the function of the optical displacement sensor. Although not specifically shown, various circuit components forming a part of the light projecting circuit, the light receiving system circuit, and the signal processing system circuit will be mounted.

An exploded perspective view showing the relationship among the case 1, the optical unit 2 and the circuit board 3 is shown in FIG.

As shown in the figure, the optical unit 2
Is a light projecting element substrate 8 on which a light projecting element is mounted, a light projecting lens 10, a light receiving element block 15 formed by holding a light receiving element substrate 14 in a light receiving element holder 28, and a light receiving lens 12 in a light receiving lens holder 29. The light receiving lens block 13 is held, and these are integrally connected via the optical base 7 which is a molded product. Optical base 7
A metal such as aluminum is adopted as a material of the above, and the positioning accuracy is improved.

An exploded perspective view showing the structure of the optical unit is shown in FIG. As shown in the figure, the light projecting element holding portion 9 for positioning and orienting and holding the light projecting element 21 on the optical base 7 is held on the optical base 7.
Is provided. The light projecting element substrate 8 on which the light projecting element 21 is mounted is screwed and fixed to the back side of the light projecting element holding portion 9. Then, the light projecting element 21 mounted on the light projecting element substrate 8 is aligned with the circular hole 9a of the holding portion 9, whereby the light projecting element 21 is positioned and oriented with respect to the optical base 7.

On the optical base 7, the projection lens 10
A light projecting lens holding portion 11 is provided for positioning, deciding and holding the optical base 7 with respect to the optical base 7.
In this example, the bottom surface of the light projecting lens holding portion 11 is a groove having a substantially V shape. A spring 23 serving as a lens pressing member is screwed and fixed to the raised support 22 adjacent to the holding portion 11. When the light projecting lens 10 is placed on the holding portion 11, the light projecting lens 10 is positioned and oriented with respect to the optical base 7 due to the direction regulating action of the V groove. Further, the light projecting lens 10 housed in the V groove forming the holding portion 11 is elastically pressed from above by the spring 23 and fixed. The space between the spring 23 and the V groove forming the holding portion can accommodate light projecting lenses of various diameters.
Therefore, depending on the difference in the distance range, the projection lens 10
Even if the length or the outer shape of the lens changes, it can be widely applied to the light projecting lenses having various specifications. Further, on the optical base 7, the light receiving element holder 28 and the light receiving lens holder 2 are provided.
A light receiving component mounting stage 39 that can be mounted by freely positioning and orienting 9 and 9 within a specified adjustment range is formed. The surface of the light receiving component mounting stage 39 is flat and parallel to a plane including the prescribed light projecting optical axis and the prescribed light receiving optical axis. In other words, this light receiving component mounting stage 3
In order to make the detection distance different, an allowance area is secured in 9 so that various arrangements of the light receiving element holder 28 or the light receiving lens holder 29 are possible.

Light receiving element substrate 14 on which the light receiving element 27 is mounted
Are screwed or caulked to the light-receiving element holder 28 having a window frame. The light receiving element holder 28 is integrally formed with brackets 28a and 28b. These brackets 28a and 28b are provided with loose holes 28e and 28f through which screws 44 and 45 are inserted. Further, on the bottom surface of the light receiving element holder 28,
Two positioning pins 28c and 28d are provided so as to project.

On the other hand, on the light receiving component mounting stage 39 of the optical base 7, the positioning pin 28 on the light receiving element holder 28 side is provided.
Positioning hole 3 with good processing accuracy for inserting c and 28d
3 and 35 and screw holes 3 into which screws 44 and 45 are screwed
7, 38 are provided.

Therefore, after inserting the pins 28c and 28d into the positioning holes 33 and 35, the screws 44 and 45 are inserted into the screw hole 3
The light receiving element 27 is positioned and oriented with respect to the optical base 7 by being screwed in the screws 7, 38.

The light-receiving element holder 28 holding the light-receiving element substrate 14 is positioned by the positioning pins 28c and 28d, and further the brackets 28a and 28b and the screw holes 3 are provided.
7 and 38 are aligned and screwed and fixed. Therefore, the optical axis of the light receiving element 27 does not deviate during attachment and detachment.

On the upper surface of the light receiving lens holder 29, a light receiving lens holding portion 31 having a V groove shape is formed. The spring 30 is screwed and fixed above the V groove that constitutes the light receiving lens holding portion 31. Therefore, when the light receiving lens 12 is placed on the holding portion 31, the optical axis of the light receiving lens 12 is oriented with respect to the light receiving lens holder 29 due to the direction regulating action of the V groove. Further, the light receiving lens 12 placed on the holding portion 31 is elastically pressed from above by the force of the spring 30 to be positioned and fixed. The space formed between the V groove forming the holding portion 31 and the spring 30 allows the light receiving lens 12 having various diameters. Therefore, the common light receiving lens holder 29 can be used even when the diameter of the light receiving lens 12 changes due to the difference in the distance range.

The light receiving lens holder 29 has a bracket 29.
a and 29b are formed. These brackets 29
Loose holes 29c and 29d through which the screws 46 and 47 are inserted are provided in a and 29b. Further, on the bottom surface of the light receiving lens holder 29, positioning pins 29e and 29f are provided so as to project.

On the other hand, on the side of the light receiving component mounting stage 39 of the optical base 7, positioning pins 3e and 29f on the side of the light receiving lens holder 29 are inserted with high precision.
4, 32 and screw holes 43 into which screws 46, 47 are screwed
And 36 are provided.

The light receiving lens holder 29 holding the light receiving lens 12 is positioned and aligned by the action of the positioning pins 29e and 29f, and then screwed and fixed by aligning the screw insertion holes 29c and 29d with the screw holes 43 and 36. It Therefore, when the light receiving lens holder 29 is attached or detached, the optical axis is not displaced.

The optical axis alignment will be described more specifically. First, the light receiving element holder 28 and the light receiving lens holder 29 are fixed on the light receiving component mounting stage 39. next,
Focusing adjustment is performed by moving the light receiving lens 12 back and forth along the light receiving optical axis. When it ’s in focus,
The light receiving lens 12 is fixed to the light receiving lens holder 29 by tightening the screw 48.

According to the optical displacement sensor having the above structure, the light projection optical axis formed by the light projecting element 21 and the light projecting lens 10 is uniquely determined with respect to the optical base 7. On the other hand, regarding the light receiving optical system including the light receiving lens 12 and the light receiving element 27, the light receiving component mounting stage 3
In FIG. 9, by moving the light receiving element 27 and the light receiving lens 12 together with the light receiving element holder 28 and the light receiving lens holder 29, an arbitrary focal length can be dealt with by changing the angle of the optical axis.

Specifically, the light receiving element holder 28 and the light receiving lens holder 29 are slid and rotated on the light receiving component mounting stage 39 to determine an appropriate position and angle, and then a hole is formed on the stage 39. The seating positions of the light receiving element holder 28 and the light receiving lens holder 29 are determined by performing opening processing, screw cutting processing, and the like.

According to such a seating structure, even if the screws are loosened, the holders 28 and 29 will not move to the positioning pin 2.
Since the positioning state is maintained by 8c, 28d, 29e, and 29f, even if the holders 28 and 29 are attached and detached, they can be accurately returned to their original seating positions, and the focus adjustment and the optical axis adjustment cannot be performed again. It becomes unnecessary.

When a plurality of optical axes having different detection ranges are assumed in advance, a plurality of combinations of positioning holes and screw holes are prepared on the stage 39 according to the respective optical axes. By doing so, even with the same light-receiving element holder 28 and the same light-receiving lens holder 29, a combination of a positioning hole and a screw hole corresponding to an appropriate light-receiving axis can be selected from among those combinations. It is possible to realize optical axes corresponding to various detection distances or detection ranges.

The detection distance (detection range) is 40 mm, 2.
4 to 6 show examples of arrangement of the light-receiving lens block 13 and the light-receiving element block 15 in the case of being different from 5 times 100 mm and 7.5 times 300 mm.

As is clear from these figures, in the present invention, the common optical base is used, but the light receiving component mounting stage 39 is provided on the optical base 7, and on this mounting stage 39. The position of the light-receiving element holder 28 and the light-receiving lens holder 29 can be freely changed and the angle can be changed, and the positioning pins 28c, 28d, 29
Since it can be positioned and fixed by using e, 29f and screws 44, 45, 46, 47, the optical base 7 that is a molded product can be used when manufacturing a plurality of types of products corresponding to various detection ranges. Since only one type is required, it is possible to significantly reduce the cost by reducing the die manufacturing cost.

Further, as shown in FIG. 7, during the adjustment work of the manufacturing process, since the light receiving lens block 13 and the light receiving element block 15 can be separated from the optical base 7, cleaning of the lens and reception of light are possible. The elements can be easily replaced, and if the blocks are returned to their original positions, the original optical axis alignment state can be reproduced by themselves, and each time, the optical axis and focal point can be reconstructed as in the conventional device. No need to re-adjust.

On the other hand, returning to FIG. 2, three bosses 18, 19 and 20 each having a screw hole at the center are integrally provided on the inner bottom surface of the case 1 which is a molded plastic product. .

On the other hand, on the optical base 7 side, hollow boss portions 24, 2 which cover these bosses 18, 19, 20 from above are provided.
5, 26 are integrally formed. The upper surfaces of the hollow boss portions 24, 25, 26 are closed in a ring shape, and a screw insertion hole is formed in the center thereof. Further, the height of the bosses 18, 19, 20 on the case 1 side is set to be slightly higher than the internal height of the hollow boss portions 24, 25, 26 on the optical base 7 side. 26,
When the boss portions 18, 19, 20 on the bottom surface of the case are covered, a slight gap is formed between the bottom surface of the optical base 7 and the inner bottom surface of the case 1.

That is, as shown in FIG.
When the hollow boss portions 26 and 24 are covered over the boss portions 20 and 18 with screw holes projecting from the bottom surface of the case from above, and the two are screwed and fixed, as shown in FIG. 8B, the case bottom plate 42 and the optical base. Between 7 and the appropriate clearance S
Is formed. In other words, the optical base 7 made of metal
Is supported by being slightly floated from the inner wall of the sensor case 1 made of plastic.

Therefore, when an external impact or a large force is applied to the case 1, the bending of the case bottom plate 42 is absorbed by the clearance S, and an excessive stress or a large stress is applied to the optical base 7. Vibration is avoided. As a result, the impact from the outside
It is possible to avoid a problem that a light emitting optical axis or a light receiving optical axis is deviated, which affects the output of the light receiving element and causes a detection error.

Further, a high degree of dimensional accuracy is provided between the outer shapes of the bosses 18, 19, 20 protruding from the bottom surface of the case 1 and the inner diameters of the hollow boss portions 24, 25, 26 on the optical base 7 side. Therefore, the boss portions 24, 25, 26 on the optical base 7 side are replaced with the boss portions 18, 19,
When the optical base 7 is press-fitted into the case 20, the optical base 7 is accurately positioned with respect to the case 1, and the screwing is performed in this state, whereby the positioning accuracy is maintained.

As described above, according to the optical displacement sensor of the present invention, the light projecting element 21 and the light projecting lens 10 are accurately positioned and oriented on the optical base 7 via the holding portions 9 and 11. It Further, the light receiving element 27 and the light receiving lens 12 are accurately positioned and oriented with respect to the optical base 7 via the light receiving element holder 28 and the light receiving lens holder 29. Further, the optical base 7 is accurately positioned and fixed via the boss portions 18, 19, 20 on the case side and the hollow boss portions 24, 25, 26 on the optical base 7 side. Therefore, while using the case 1 that is lightweight and easy to bend in terms of strength, it is possible to maintain accurate positioning of the optical components, and thus it is possible to provide a lightweight and accurate optical displacement sensor.

In addition, if the sensor head (case) is attached to a predetermined attachment object with the attachment hole 6 of the case 1, the case 1 and the optical base 7 can be aligned with each other.
The desired exit angle and incident angle are obtained. In other words, the projection / reception optical axis can be obtained with the outer shape of the case as a reference.

Further, unlike the conventional block-shaped optical unit, the optical unit 2 and the circuit board 3 are superposed and housed in a case because the optical unit can be made thin according to the diameter of the lens. Therefore, it is possible to reduce the space of the circuit board and realize miniaturization as compared with a conventional circuit board in which the circuit boards are arranged adjacent to each other.

Further, unlike the conventional lens-inserted and held lens in the tunnel-shaped passage, since the entire circumference of the lens is not surrounded, the light projecting lens 10 and the light receiving lens 12 are moved in the direction orthogonal to the optical axis. It can be attached and detached, and there is no need to readjust the position and orientation of the optical axis when attaching and detaching.

Further, the light-receiving element holder 28 and the light-receiving lens holder 29 can be arbitrarily positioned and oriented on the light-receiving component mounting stage 39, and are optical products which are molded products by drilling or threading. The base 7 can be attached and detached by post-processing. Therefore, even when a plurality of types of models having different distance ranges are required, the optical base 7 can be used as a common component, and the cost of the molding die can be reduced, which enables a significant cost reduction.

Further, since the holding portion 11 of the light projecting lens 10 and the holding portion 31 of the light receiving lens 12 each have a V-shape, the direction can be easily determined only by mounting the light projecting lens 10 and the light receiving lens 12. Moreover, since the springs 23 and 30 are used as the pressing member, it is possible to easily cope with an arbitrary lens diameter.

Further, while using a lightweight plastic as the case, the optical base made of metal is supported so as to be slightly floated above the inner wall of the sensor case made of plastic. Even when a force is applied, the optical components do not move and the optical axis is not displaced, and a highly reliable detection result or measurement result can be obtained. In addition, if the sensor case is made of plastic, the electrical insulation between the optical unit 2 and the case 1 is not required, the interposition of an insulating plate is not required, and the cost is further reduced by reducing the size and the number of parts. It will be possible.

The characteristic structure of the present invention can be applied not only to the optical displacement sensor but also to a distance setting type photoelectric sensor.

That is, in such a photoelectric switch, the optical unit and the circuit board are housed in the switch case. The optical unit includes a light projecting element, a light projecting lens, a light receiving element holder that holds a light receiving element, and a light receiving lens holder that holds a light receiving lens, which are integrally formed via an optical base that is a molded product. Are combined.

On the optical base, a light projecting element holding portion for positioning, orienting and holding the light projecting element with respect to the optical base, and a light projecting lens for positioning and orienting with respect to the optical base. A light emitting lens holding portion for holding the light receiving element holder, and a light receiving component free mounting stage on which the light receiving element holder and the light receiving lens holder can be mounted by freely positioning and orienting within a prescribed adjustment range are formed.

Accordingly, even for a plurality of models having different distance ranges, by adjusting the positions and directions of the light receiving element holder and the light receiving lens holder on the stage for freely mounting the light receiving component, the corresponding light receiving optical axis can be realized. It is possible to prepare multiple models with one optical base.

At this time, the switch case may be made of plastic, and the optical base, the light receiving element holder, and the light receiving lens holder may be made of metal.

In such a photoelectric switch, the optical unit and the circuit board are housed in the switch case. The optical unit includes a light projecting element, a light projecting lens, a light receiving element, and a light receiving lens, which are integrally coupled via an optical base that is a molded product. Plastic is used as the material of the sensor case, and metal is used as the material of the optical base.

[0096]

As is apparent from the above description, according to the present invention, the optical displacement sensor of this type can be reduced in size and weight and reduced in cost.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an internal configuration of a displacement sensor of the present invention.

FIG. 2 is an exploded perspective view showing a relationship between a case, an optical unit and a circuit board.

FIG. 3 is an exploded perspective view showing a configuration of an optical unit.

FIG. 4 is an explanatory diagram showing an arrangement of a light emitting / receiving optical system of a displacement sensor in which a detection distance is set to 40 mm.

FIG. 5 is an explanatory diagram showing an arrangement of a light emitting / receiving optical system of a displacement sensor in which a detection distance is set to 100 mm.

FIG. 6 is an explanatory diagram showing an arrangement of a light emitting / receiving optical system of a displacement sensor in which a detection distance is set to 300 mm.

FIG. 7 is a diagram showing a disassembled state during maintenance work.

FIG. 8 is an explanatory diagram of a support structure for an optical base.

FIG. 9 is a diagram showing a configuration of a conventional displacement sensor.

FIG. 10 is a diagram showing a configuration of a conventional optical unit.

[Explanation of symbols]

1 sensor case 2 Optical unit 3 circuit board 4 cover plate 5 window boards 6 mounting holes 7 Optical base 8 Projector substrate 9 Projector element substrate holder 10 Projection lens 11 Emitter lens holding part 12 Light receiving lens 13 Light receiving lens block 14 Light receiving element substrate 15 Light receiving element block 16 Floodlight window 17 Light receiving window 18, 19, 20 Boss 21 Projector 22 units 23 Spring 24, 25, 26 Hollow boss 27 Light receiving element 28 Light receiving element holder 28a, 28b bracket 29 Light receiving lens holder 30 springs 31 Light receiving lens holder 28c, 28d, 29e, 29f Positioning pin 36, 37, 38, 43 screw holes 39 Light receiving component mounting stage 40, 41 screws 42 Case bottom plate 44, 45, 46, 47 Set screw 48 screws S clearance

Continued front page    (72) Inventor Yuichi Inoue             Shimogyo-ku, Kyoto-shi Shioji-dori Horikawa Higashiiri Minamifudo-cho             801 OMRON Corporation F term (reference) 2F065 AA06 DD02 DD04 FF09 JJ16                       PP01 PP22 UU03                 2F112 AA02 BA07 BA10 CA13 DA32                 2H044 AA03 AA15                 2H051 BB20 CA12 CA16 CA18

Claims (20)

[Claims] 1. An optical unit and a circuit board are housed in a sensor case, and the optical unit holds a light projecting element, a light projecting lens, a light receiving element holder for holding the light receiving element, and a light receiving lens. And a light-receiving lens holder, which are integrally connected via a molded optical base. The light-projecting element is positioned and oriented with respect to the optical base and is held on the optical base. For holding the light emitting element, a light emitting lens holding portion for positioning and orienting and holding the light emitting lens with respect to the optical base, and a light receiving component mounting stage to which the light receiving element holder and the light receiving lens holder are attached Is formed as a means for positioning and mounting one or both of the light receiving element holder and the light receiving lens holder on the light receiving component mounting stage. Pins and setscrews are used, and by positioning the positioning holes and screw holes differently on the stage for mounting the light-receiving component, it is possible to use the same light-receiving element holder or light-receiving lens holder, but place holders with different detection distances. Therefore, even for multiple models with different distance ranges, the position and orientation of the light-receiving element holder and the light-receiving lens holder on the light-receiving component mounting stage can be adjusted to adjust the corresponding light-receiving optical axis. By realizing it, an optical displacement sensor that can prepare multiple models with one type of optical base. 2. The optical displacement sensor according to claim 1, wherein the light receiving component mounting stage is parallel to a plane including a prescribed light projecting optical axis and a prescribed light receiving optical axis. 3. The optical displacement sensor according to claim 1, wherein a plurality of positioning holes and fixing screw holes are pre-drilled in the light receiving component mounting stage to accommodate a plurality of models having different detection ranges. . 4. The optical displacement according to claim 1, wherein the light projecting lens held by the light projecting lens holder is detachable in a direction orthogonal to the light projecting optical axis while maintaining its orientation. Sensor. 5. The optical displacement sensor according to claim 1, wherein the light-receiving lens held by the light-receiving lens holder is attachable / detachable in a direction orthogonal to the light-receiving optical axis while maintaining its orientation. 6. The optical element according to claim 1, wherein the light-receiving element holder and the light-receiving lens holder mounted on the light-receiving component mounting stage are attachable / detachable in a direction orthogonal to the light-receiving optical axis while maintaining their orientations. Displacement sensor. 7. The optical displacement sensor according to claim 1, wherein the light projecting lens holding portion is provided with a lens holding structure capable of holding a plurality of types of light projecting lenses having different diameters. 8. The optical system according to claim 7, wherein the lens holding structure includes a V groove that orients the light projecting lens and a pressing member that elastically presses the light projecting lens against the V groove. Displacement sensor. 9. The optical displacement sensor according to claim 1, wherein the light receiving lens holder is provided with a lens holding structure capable of holding a plurality of types of light receiving lenses having different diameters. 10. The optical displacement according to claim 9, wherein the lens holding structure includes a V groove that orients the light receiving lens and a pressing member that elastically presses the light projecting lens against the V groove. Sensor. 11. The optical displacement sensor according to claim 1, wherein the circuit board is arranged over the optical unit in the sensor case. 12. The optical displacement sensor according to claim 1, wherein the sensor case is made of plastic, and the optical base, the light receiving element holder, and the light receiving lens holder are made of metal. 13. The optical displacement sensor according to claim 12, wherein a press-fitting technique is adopted as a means for fixing the optical unit made of metal in the sensor case made of plastic. 14. The optical displacement sensor according to claim 12, wherein the optical base made of metal is supported so as to be slightly floated from the inner wall of the sensor case made of plastic. 15. The light receiving element included in the optical unit is P
The optical displacement sensor according to claim 14, which is an analog output type device such as SD. 16. An optical unit and a circuit board are housed in a sensor case, and the optical unit includes a light projecting element, a light projecting lens, a light receiving element, and a light receiving lens, which are molded products. Is an optical displacement sensor that is integrally connected via an optical base, which is made of plastic as the material of the sensor case, and metal as the material of the optical base. 17. The circuit board is arranged over the optical unit in the sensor case in an overlapping manner.
The optical displacement sensor according to. 18. The optical displacement sensor according to claim 16, wherein the optical base made of metal is supported by being slightly floated from the inner wall of the sensor case made of plastic. 19. The light receiving element included in the optical unit is P
The optical displacement sensor according to claim 18, which is an analog output type device such as an SD. 20. The optical displacement sensor according to claim 16, wherein a press-fitting technique is adopted as a means for fixing the optical unit made of metal in the sensor case made of plastic.