JPH09250903A - Optical displacement sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical type displacement sensor wherein assembly process of the entire sensor is smooth by making assembly of a lens-barrel provided with a lens and a glass filter easy. SOLUTION: A floodlight lens and a photodetecting lens are bonded to the inside of floodlight side and photodetecting side lens-barrels 13 and 23 inserted and fixed to circular holes 41 and 42 an the end surface of a sensor head 30, respectively. And further, to its end surface, a floodlight glass filter 12 and a photodetecting glass filter 22 are bonded in advance, respectively, so that, at assembly process for the entire sensor, bonding process for the glass filter is not required.

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 to be measured by irradiating the object to be measured with a light beam and receiving reflected light from the object to be measured.

[0002]

2. Description of the Related Art An optical displacement sensor of this type is shown in FIG.
The schematic configuration is as shown in. In the optical displacement sensor shown here, the light beam of the light projecting element (for example, a semiconductor laser) 10 is irradiated onto the object 50 to be measured through the light projecting lens 11 and the light projecting glass filter 12, and is reflected from the object 50 to be measured. Light is received by a light receiving element (for example, a one-dimensional detection element) 20 via a light receiving glass filter 22 and a light receiving lens 21.

As shown in FIG. 4, the light projecting lens 11 and the light receiving lens 21 are adhered inside the lens barrels 13 and 23, respectively, and the lens barrels 13 and 23 (lenses with lens barrels) are located at predetermined positions of the sensor head 30. It is fitted into the circular holes 41 and 42 formed in the above and is fixed to the sensor head 30 by screwing screws 37 and 38 into the screw holes 35 and 36. Further, in many cases, the light projecting glass filter 12 ′ and the light receiving glass filter 22 ′ are bonded by using the bonding margins (hatched portions) 43 and 44 provided on the end surface of the sensor head 30, respectively, so that the mirror The end faces of the cylinders 13 and 23 are glass filters 1.
Closed at 2 ', 22'.

The light projecting and receiving glass filter 12 ',
22 'is not only for blocking ambient light, but also for the lens barrel 1
If the light projecting and light receiving lenses 11 and 21 in the lenses 3 and 23 are left exposed, the lens surfaces are contaminated, so that they are provided to protect the lens surfaces. For example, even if the glass filter gets dirty, it has a certain area larger than that of the lens, and therefore the dirt can be easily wiped off.

[0005]

However, the work of adhering the glass filter to the end face of the sensor head is not so easy. For example, if the inside of the glass filter (on the side facing the lens) is adhered to the end surface of the sensor head 30 while it is dirty, the dirt cannot be wiped off later, and therefore the glass filter must be adhered carefully. For the adhesion, an adhesive may be used or a double-sided tape may be used, but in either case, the assembling work is not easy.

Therefore, the present invention has been made in view of such problems, and facilitates the assembly of the lens barrel having the lens and the glass filter, thereby facilitating the assembly process of the entire sensor. An object is to provide an optical displacement sensor.

[0007]

In order to achieve the above object, in the optical displacement sensor of the present invention, a sensor head receives a light beam from a light projecting element through a light projecting lens and a light projecting glass filter. A light projecting means for projecting light onto a measurement object, a light receiving means for receiving reflected light from the measurement object through a light receiving glass filter and a light receiving lens, and a distance to the measurement object is measured based on an output of the light receiving means. At least one of the light projecting lens and the light receiving lens is adhered inside a lens barrel, a corresponding glass filter is bonded to an end face of the lens barrel, and the lens and the glass filter are bonded and integrated. The formed lens barrel is attached to the sensor head.

In this optical displacement sensor, a glass filter is previously attached to the end surface of the lens barrel having the lens adhered therein, the glass filter is integrated with the lens barrel, and the lens barrel with the glass filter is used as the sensor. Mount on the head. Therefore, it is possible to perform the glass filter bonding process that requires extreme caution against dirt, so that the assembly process of the entire sensor can be performed smoothly without the labor and time required for the glass filter bonding process. it can.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments. The present invention is characterized in that a glass filter is bonded to the end surface of the lens barrel in advance, and other configurations are the same as the conventional ones, and therefore, the same elements are denoted by the same reference numerals. FIG. 1 shows a partially omitted perspective view of a sensor head and a lens barrel with a glass filter according to the embodiment. In this embodiment, the light-projecting-side lens barrel 13 has the light-projecting lens 11 adhered therein, as shown in the sectional view of FIG.
The light projecting glass filter 12 is bonded to the end face, and the light projecting lens 11 and the light projecting glass filter 12 are integrated. Of course, the lens barrel 23 on the light receiving side has the same structure.

The sensor head 30 has a lens barrel 1 on its end face.
3 and 23 have circular holes 41 and 42 into which the glass filters 12 and 22 on the end faces of the lens barrels 13 and 23 are mounted in the sensor heads. It is set so as to be located on the end face of 30.
The lens barrels 13 and 23 are screw holes 35 and 3 of the sensor head 30.
Circular holes 41, 42 by screws 37, 38 screwed to the 6
Fixed to

As described above, the glass filters 12 and 22 are previously prepared.
By adhering to the end faces of the lens barrels 13 and 23 and integrating them, that is, by assembling a lens barrel with a glass filter, the bonding process (lens bonding process and glass filter bonding process) is performed. Since the process of assembling the entire sensor can be separated, the process of assembling the entire sensor can be made smooth. Further, as can be seen from comparison with the conventional example of FIG. 4, a bonding margin (hatched portion) 43, for bonding the glass filters 12, 22 to the end surface of the sensor head 30,
Since it is not necessary to provide 44, the glass filters 12, 2
The size of 2 can be reduced, and the outer shape of the sensor can be reduced accordingly.

The structure of the entire optical displacement sensor is, for example, as shown in FIG. That is, the light beam from the light projecting element 10 is applied to the object 50 to be measured through the light projecting lens 11 and the light projecting glass filter 12, and the reflected light from the object 50 to be measured is the light receiving glass filter 22 and the light receiving lens 21. Then, the light is received by the light receiving element 20. The light projecting element 10 is attached to the light projecting element holding base material 15, and the projection of the light beam is controlled by the light projecting circuit board 16. The light receiving element 20 is attached to the light receiving element holding base material 25, the light receiving signal is input to the light receiving circuit board 26, and the arithmetic circuit (arithmetic means) 31 calculates the distance to the measured object 50.
The displacement data is output.

In the above-described embodiment, the glass filters 12 and 22 are preliminarily adhered to both the light projecting side and the light receiving side lens barrels 13 and 23, but either one may be used. In this case, if the glass filter is not adhered to the end surface of the lens barrel, the glass filter is adhered to the end surface of the sensor head as in the conventional case.

[0014]

As described above, according to the optical displacement sensor of the present invention, the glass filter is adhered to the end face of the lens barrel in advance and integrated with the lens. It suffices to attach the lens barrel with the filter to a predetermined position of the sensor head, and the troublesome step of adhering the glass filter at the time of the assembly step becomes unnecessary. Therefore, the adhesion process, which requires extreme caution against dirt,
Since it can be separated from the assembly process of the sensor body,
The entire sensor assembly process is smooth.

Further, conventionally, since it is necessary to provide a bonding margin for bonding the glass filter to the end surface of the sensor head, the outer shape of the sensor is increased by that much, but in the present invention, such a bonding margin is unnecessary. Therefore, the outer shape of the entire sensor can be reduced.

[Brief description of drawings]

FIG. 1 is a partially omitted perspective view showing a sensor head and a lens barrel with a glass filter according to an embodiment.

FIG. 2 is a cross-sectional view of the lens barrel with a glass filter of FIG.

FIG. 3 is a diagram showing a schematic configuration of an optical displacement sensor.

FIG. 4 is a partially omitted perspective view showing a sensor head, a glass filter, and a lens barrel according to a conventional example.

[Explanation of symbols]

 10 Light-Emitting Element 11 Light-Emitting Lens 12 Light-Emitting Glass Filter 13 Lens Tube 20 Light-Receiving Element 21 Light-Receiving Lens 22 Light-Receiving Glass Filter 23 Lens Tube 30 Sensor Head 50 Object to be Measured

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinya Otsuki 10 Ouron Co., Ltd., Hanazono Dodocho, Ukyo-ku, Kyoto City, Kyoto Prefecture

Claims (1)

[Claims] 1. A light projecting means for projecting a light beam from a light projecting element onto a sensor head through a light projecting lens and a light projecting glass filter, and a light receiving glass for reflected light from the object to be measured. An optical displacement sensor comprising: a light receiving means for receiving light through a filter and a light receiving lens; and a computing means for measuring a distance to an object to be measured based on an output of the light receiving means, wherein at least one of the light projecting lens and the light receiving lens. Is attached to the inside of a lens barrel, a corresponding glass filter is attached to an end surface of the lens barrel, and a lens barrel in which the lens and the glass filter are integrally bonded is attached to the sensor head. Displacement sensor.