KR980011558A - Multi beam sensor - Google Patents

Abstract

The thickness of the sensor main body is made thin, the influence of electrical disturbance is suppressed, and the fall of the light receiving efficiency of the reflected light beam is prevented.

The light emitting element 5 which transmits several light beams 12a-12c to the other direction of space, and the light beams 13a-13c reflected in the said space are made by the several light receiving elements 9a-9c. In a multi-beam sensor that individually receives light, the light receiving prisms 21b and 21c which deflect the optical axes of the plurality of light beams 13a to 13c in a predetermined direction, and the light receiving prisms 21b and 21c in a predetermined direction. A light receiving lens 20a to 20c which forms the converted light beams 13a to 13c in a plurality of light receiving elements 9a to 9c in a one-to-one manner, at least equal to the number of light beams 12a to 12c. The elements 9a-9c are arrange | positioned on the same plane.

Description

Multi beam sensor

Since this is an open matter, no full text was included.

1 is a cross-sectional view showing a conventional multi-beam sensor.

1a is a side view.

1b is a front view.

2 is a perspective view showing an optical system of a multi-beam sensor.

3A shows a multi-beam light source.

3B is a view showing a state in which a reflected light beam is focused on a light receiving element three-dimensionally arranged.

4 is a perspective view showing an optical system of the multi-beam sensor of the first embodiment.

5A is a diagram showing a light-receiving lens arranged in a plane.

5B is a view showing a state where a reflected light beam is incident on a prism (part of the optical axis conversion element).

6 is a perspective view showing an optical crab of the multi-beam sensor of the second embodiment.

7 is a diagram in which non-diffraction shows an optical system of a multi-beam sensor.

8 is a cross-sectional view of a light receiving side of a multi-beam sensor provided with a pinhole mask.

9 is a cross-sectional view of a light receiving side of the multi-beam sensor of the third embodiment.

10A is a diagram showing an integrated element in which a prism array and a light receiving lens are integrated.

10B is a perspective view showing an integrated element in which a prism and a light receiving lens are integrated.

11 is a cross-sectional view of a light receiving side of a multi-beam sensor according to a fourth embodiment.

12 is an exploded perspective view illustrating a multi-beam sensor according to a fifth embodiment.

Fig. 13 is a perspective view showing an electronic copy device of the sixth embodiment.

14 shows a multi-beam light source.

15 is a view showing an example of a moving object detection apparatus using a multi-beam sensor.

16 is a diagram in which the multi-beam sensor of the present invention is mounted on an ATM.

Fig. 17 is a diagram in which the multi-beam sensor of the present invention is mounted on a personal computer.

* Explanation of symbols for main parts of the drawings

2: light transmitting lens 9a to 9c: light receiving element

20a-20c: Light receiving lens 21b, 21c: Prism

22: optical axis conversion element 30, 31, 33: integral element

Detailed description of the invention

[Purpose of invention]

[Technical Field to which the Invention belongs and Prior Art in the Field]

The present invention relates to a multi-beam sensor that transmits a plurality of light beams to an object, receives the reflected light, and the object detects a physical quantity. The multi-beam sensor is used for the detection of an original size in an electronic copier, the detection of a human body, the detection of moving objects, and the like.

As a sensor for judging the size of the paper mounted in a copying machine or the like, detecting the presence or absence of the paper at various points using a plurality of light beams is the basic configuration of the Patent Publication No. 3-175305 by Omron Corporation. This is described. The configuration disclosed herein divides the emitted light of one light emitting element into a plurality of light beams, projects the plurality of light ratios onto a glass surface that is a platen glass, and reflects a beam of reflected light from the sheet placed on the platen through a light receiving lens. It guides to the several light receiving element provided corresponding to the reflected light beam. In order to split the emitted light of the light emitting element, a lens array including a plurality of off-axis funnel lenses is used. As the plurality of light receiving elements, a light receiving element array arranged in a plane is used.

Applicant's Patent Publication No. 5-58510 by OMRON Corporation discloses an improved configuration of a light receiving portion of a multi-beam sensor for determining the size of a paper. That is, by arranging the plurality of light receiving elements in the image forming position by the light receiving lens of the reflected light toward the incident direction, the sensor can be made compact and the light receiving efficiency can be improved. As a result, the light receiving element is arranged in three dimensions rather than being disposed on a plane.

The thing which supplemented the support structure etc. of the periphery to the structure of said Unexamined-Japanese-Patent No. 5-58510 is shown to FIG. 1 (a) and (b). On the upper surface of the rectangular body case 1, a large-diameter translucent lens 2 and a light receiving lens 3 are mounted via a spacer 4. On the side of the light transmitting lens 2, a rotating substrate 8 such as a multi-beam light source and an amplifier circuit composed of the LED 5 and the grating 6 is provided. Further, a processing circuit board for discriminating an original size or the like based on the detection signals of the three light receiving elements 9a, 9b, 9c and the light receiving elements 9a, 9b, 9c three-dimensionally arranged below the light receiving lens 3. (10) is built in. Moreover, the bottom face of the main body case 1 which contacts a copy machine etc. is insulated by the insulating sheet 11.

As shown in FIG. 2, the optical system of the multi-beam sensor collimates the light beam 12 from the LED 5 with the light-transmitting lens 2 and then three diffracted light 12a with the grating 6. 12b, 12c, and irradiated to a detector such as an original, and the reflected light beams 13a, 13b, 13c are imaged on the light receiving elements 9a, 9b, 9c individually through one light receiving lens 3. It is supposed to be.

As shown in (a) of FIG. 3, the multi-beam light source uses the light beam 12 of the LED 5 by the grating 6 to the 0th order diffracted light 12a and the ± 1st order diffracted light 12b. 12c), and the diffracted light 12a, 12b, 12c irradiated onto the detector has the strongest light intensity of the zeroth order diffracted light 12a, and the first diffracted light 12b, 12c. 37 degrees inclined with respect to (12a) of the O-order. The light receiving elements 9a, 9b, and 9c are disposed at three condensing positions where the respective reflected light beams 13a, 13b, and 13c are imaged by the light receiving lens 3, as shown in Fig. 3B. And the reflections and the beams 13a, 13b, and 13c are directed in the optical axis direction. For this reason, each light receiving element 9a, 9b, 9c has a three-dimensional arrangement.

[Technical problem to be achieved]

However, the conventional multi ratio sensor had the following problems.

(1) Since the reflected light beams 13a, 13b, 13c from the detector are obliquely incident on the light receiving lens 3 outside the optical axis, the condensed positions of the respective reflected light beams 13a, 13b, 13c deviate in the optical axis direction. The light receiving elements 9a, 9b, and 9c need to be arranged in three dimensions, and for that purpose, the thickness of the sensor main body must be thickened.

(2) Each circuit board (8, 10) is required in the light receiving system and the light transmitting system, and a three-dimensional substrate arrangement (two circuit boards (8, 10) are arranged to be orthogonal to each other in FIG. 1) is assembled. Bad sex

(3) Since the light receiving elements 9a, 9b, 9c are three-dimensionally arranged, the wiring from the light receiving elements 9a, 9b, 9c to the circuit board 10 such as the amplifier circuit is crawled, and therefore, such as electromagnetic noise Weak in electric disturbance

(4) Since the reflected light beams 13b and 13c are incident from outside the optical axis of the large-diameter light-receiving lens 3, the light receiving spots of the ± first-order diffraction steels 12b and 12c are caused by off-axis aberration (astigmatism). 9c) could not be condensed sufficiently.

This invention is made in view of the fault of the said prior art, The objective is to make the thickness of a sensor main body thin, to suppress the influence of an electrical disturbance, and to prevent the fall of the light reception efficiency of a reflected light beam.

Another object of the present invention is to provide an advantage of multi-point detection using a plurality of light beams for any kind of sensor used for a purpose other than the detection of the original size.

[Configuration and Function of Invention]

The multi-beam sensor according to claim 1 of the present invention comprises a light transmitting portion for emitting a plurality of light beams in a different direction of the space, and a plurality of light receiving elements for individually receiving each reflected light beam reflected by the object. A multi-beam sensor, comprising: means for converting optical axes of the respective reflected light beams reflected from an object to be substantially parallel to each other, and imaging optics disposed on the optical axes of each of the reflected light beams provided substantially parallel by the optical axis converting means An element and a light receiving element are provided.

However, after a plurality of light beams emitted from the light transmitting portion are reflected by the object, the optical axes are converted by the optical axis converting means so that the optical axes are parallel to be formed on the light receiving element by the imaging optical element.

Since the reflected optical beams incident on the imaging optical element and the light receiving element are provided in parallel by the optical axis converting means, the entire optical element and the light receiving element can be arranged on the same plane, thereby reducing the thickness of the multi-beam sensor. can do.

Further, since all of the reflected light beams can be incident perpendicularly to each of the optical elements and the light receiving elements of the binder, a decrease in the light receiving efficiency due to off-axis aberration and the like of the optical element for imaging can be prevented. Moreover, since the optical elements for imaging are provided respectively facing each light receiving element, it can form an image on a light receiving element using the light ray near the axis of each optical element for imaging, and the influence of aberration can be reduced more.

In addition, since there is no need to arrange the light receiving elements three-dimensionally, each light receiving element and the light transmitting portion can be integrated into a unified circuit board to improve the assemblability, and shorten the circuit wiring from the light receiving element to the amplifier circuit. It can reduce the effects of electrical disturbance by.

An embodiment according to claim 2 is characterized in that in the multi-beam sensor according to claim 1, the optical axis converting means changes the optical axis direction of one reflected light beam by one or two prisms. .

A prism can be used for the part which needs to change the optical axis direction of an optical axis conversion means. In particular, when the optical axis of one reflected light beam is changed by two or more prisms (prism array), the thickness of the optical axis converting means can be reduced, and the multi-beam sensor can be further thinned.

An embodiment of claim 3 is characterized in that, in the multi-beam sensor according to claim 1, the optical axis converting means and the plurality of imaging optical elements are integrally formed.

Thus, by integrating the imaging optical element and the optical axis converting means, the component cost can be reduced, the number of assembly steps can be simplified, and the sensor main body can be reduced.

An embodiment of claim 4 is characterized in that the optical axis converting means or the imaging optical element is formed in a case in which the light receiving element is housed.

Thus, by providing the optical axis converting means and the imaging optical element in the case, the number of parts can be reduced, and the assembly can be simplified and the cost can be reduced.

The electromagnetic radiation apparatus according to claim 5 is output from a multi-beam sensor according to claims 1 to 4 arranged to emit a plurality of light beams toward a document glass, and from each light receiving element of the multi-beam sensor. And means for discriminating the size of the original based on the detection signal.

Since the multi-beam sensor of the present invention can be thinned, it does not occupy a mounting space when mounted in the electronic copy device, and contributes to the miniaturization of the electronic copy device.

(1st embodiment)

As shown in FIG. 4, the light transmitting portion of the multi-beam sensor of the present embodiment collides the light beam 12 from the LED 5 with the light-transmitting lens 2, and then the 3 The light is divided into two diffracted lights 12a, 12b, and 12c and irradiated to a detector such as an original. As a means for dividing the light beam, a lens array composed of a plurality of lenses having different optical axes as described in the above-mentioned Patent Publication No. 3-175303 may be used. Instead of the lens constituting the lens array, a prism or a prism array used in the light receiving unit described later may be used. The same applies to the light transmitting portion of another embodiment described later.

As shown in FIG. 4, the multi-beam sensor of the present embodiment has an optical axis converting element for deflecting the optical axes of the two reflected light beams 13b and 13c in a predetermined direction above the three light receiving lenses 20a, 20b and 20c. 21) is different from the conventional multi-beam sensor in that it is disposed. In addition, the same code | symbol is attached | subjected to the member like the conventional multi-beam sensor.

The optical axis converting element 21 is formed of a light-transmissive material having a refractive index greater than 1, and prism 21b, 21c inclined toward the inside of the left and right upper surfaces is formed on both sides of the flat plate 21a. And the prism 21b, 21c is arrange | positioned so that the reflected light beam 13b, 13d of rotation light of +/- 1st order may be transmitted.

FIG. 5A is a view showing a light receiving system of a multi-beam sensor, wherein the light receiving lenses 20a, 20b, and 20c are arranged so that optical axes are parallel to each other, and each light receiving element 9a, such as a photodiode or phototransistor, is provided. 9b and 9c are arrange | positioned in the same plane so that each light receiving surface may become perpendicular to the optical axis of the light receiving lenses 20a, 20b, and 20c. The reflected light beams 13a, 13b, 13c of the light beams 12a, 12b, 12c projected onto the object (hereinafter referred to as the original surface) by the multi-beam light source are three light receiving lenses 20a, 20b, and 20c. It forms on three light receiving elements 9a, 9b, and 9c. At that time, the reflected light beams 13b and 13c of the diffraction light 12b and 12c having the first order incident from the inclination are centered by the prisms 21b and 21c arranged on the original side of the light receiving lenses 20b and 20c. The optical path is changed so as to be parallel to the reflected light beam 13a, and all the reflected light beams 13a, 13b, 13c are incident almost perpendicularly to the light receiving elements 9a, 9b, 9c provided on the bottom. That is, the light receiving spots collected by the light receiving lenses 20a, 20b, and 20c are formed in the light receiving elements 9a, 9b, and 9c provided on the same plane.

As a result, the light receiving elements 9a, 9b, and 9c can be discharged on the same plane, and the thickness of the sensor main body can be reduced.

FIG. 5B is a diagram illustrating a state in which the reflected light beam 13c is incident on the prism 21c. The reflected light beam 13c of the diffraction light 12c of the ± 1st order projected on the original surface 50 mm apart from the 0th order light at a distance of 32.5 mm is prism 21c at an angle of inclination of 27.5 degrees with respect to the optical axis of the light receiving lens 20. ). At this time, when the refractive index of the optical axis converting element 21 is 1.59, the inclination angle of the prism 21c is 33 degrees, and the reflected light beam 13c is vertically transmitted from the bottom of the prism 21c. That is, since the optical path is changed in the optical axis direction of the light receiving lens 20c, the influence of the off-axis aberration is eliminated, and the condensing spot becomes large and leaks out of the light receiving element 9, such as the light obliquely incident on the light receiving lens 20c. There is no work, and the light reception efficiency can be improved.

(2nd embodiment)

In this embodiment, as shown in Fig. 6, in the multi-beam sensor of the first embodiment, the optical axes of the three reflected light beams 13a, 13b, 13c are fixed above the light receiving lenses 20a, 20b, 20c. The optical axis conversion element 22 which deflects in the direction is provided, and the pinhole mask 23 (refer FIG. 8) is arrange | positioned between the light receiving lenses 20a, 20b, and 20c and the light receiving elements 9a, 9b, and 9c. . In addition, the same code | symbol is attached | subjected to the member like the multi-beam sensor of 1st Embodiment. In addition, in order to transmit three light beams 12a, 12b, and 12c, the light beam 12 from a single LED 5 is separated into diffracted light 12a, 12b, and 12c of 0th order and ± 1st order. Although the grating 6 which transmits light to the discriminating object is provided, as shown in FIG. 7, three LEDs 5a, 5b and 5c may be used instead of the grating 6.

The optical axis conversion element 22 is formed by forming prism arrays 22b and 22c on the flat plate 22a, and a plurality of prisms are arranged in an array shape. When the array dividing number is n, the thickness can be reduced to 1 / n of the normal prism. Thereby, the sensor main body can be thinned. In addition to converting the optical axis by the refraction of the light, the prism array may also convert the optical axis by diffraction of light in which the unit prism constituting the prism array has a size of about several μm.

As shown in Fig. 8, the pinhole mask 23 has three holes for passing the condensing spots of the reflected light 13a, 13b, 13c through the light shield 24 to prevent noise light caused by other disturbance light or stray light. (25a, 25b, 25c) are installed through. The light shield 24 is a rectangular box with an open bottom. Moreover, the same effect is acquired also when using the elongate slit knife edge instead of the pinhole mask 23. FIG.

(Third embodiment)

In the present embodiment, in the first or second embodiment, as shown in FIG. 9, an integrated element in which the light receiving lenses 20a, 20b, and 20c and the prisms 22b and 22c are integrally formed on the flat plate 22a. 30 is installed. FIG. 10A shows an integrated element 30 in which the prism arrays 22b and 22c and the light receiving lenses 20a, 20b and 20c are integrated in the front and back, and FIG. 10 (b) shows the prism 21b, 21c) and the light receiving lens 20a, 20b, and 20c show the integrated element 31 integrated in the front and back. As such, by integrating the light receiving lenses 20a, 20b, and 20c with the prisms 21b and 21c, the cost of each component such as the light receiving lenses 20a, 20b, and 20c can be reduced, the number of simmering processes can be simplified, and the sensor can be integrated. The main body can be thinned.

(4th embodiment)

In this embodiment, in the multi-beam sensor of the second embodiment, the light transmitting lenses (not shown) and the light receiving lenses 20a, 20b, and 20c become Fresnel lenses, and the thickness is reduced. As shown in FIG. 11, the light receiving lenses 20a, 20b, and 20c formed by the Fresnel lens are formed as an integrated element 38 integrated with the prism arrays 22b and 22c to realize a significantly thinner thickness. Further, by using the light receiving lenses 20a, 20b, and 20c of the integrated element 33 as Fresnel lenses, the knitting of the light receiving lenses 20a, 20b, and 20c is reduced, and the molding fluidity at the time of injection molding is increased to provide It has the advantages of writing.

(5th embodiment)

In this embodiment, in the multi-beam sensor of 2nd Embodiment, as shown in FIG. 12, the optical-axis conversion element 22 and the grating 6 are integrally shape | molded on the upper surface in the main body case 1. As shown in FIG.

Thus, by integrating the optical axis conversion element 22 and the grating 6 in the main body case 1, the assembly is simplified and the parts are saved. In addition, since it is not necessary to arrange the light receiving elements 9a, 9b, and 9c in three dimensions, the light receiving elements 9a, 9b and 9c, the circuit, the LED 5, and the circuit can be integrated in one substrate 35. . As a result, the assemblability can be further improved, and the circuit wiring 36 from the light receiving elements 9a, 9b, 9c to the amplifier circuit can be shortened, and the influence of electrical disturbance due to electronic noise can be reduced. Can be. Reference numeral 37 denotes an input / output connector, 38 denotes a support case for supporting the LED 5, and 39 denotes a support for supporting the light receiving lenses 20a, 20b, and 20c and the light transmitting lens 2. In addition, the light receiving lenses 20a, 20b, and 20c are integrally formed on the lower surface of the main body case by facing the optical axis conversion element 22, and the translucent lens 2 is disposed on the lower surface of the main body case 1 by opposing the grating 6. Integrally molded, and the support 39 becomes unnecessary, so that the multi-beam sensor can be reduced in weight and size.

(6th Embodiment)

In this embodiment, as shown in FIG. 13, the multi-beam sensor 42 is attached below the glass plate (glass plate) 41 of the electromagnetic copying device 40 as a detector of the document size discriminating means. As shown in FIG. 14, the multi-beam sensor 42 measures diffraction light 12a, 12b, and 12c of the original 44 divided by three of the multi-beam light source 43 into three dimensions. The light beams 13a, 13b, and 13c are projected at a position corresponding to the size, so that the light beams 13a, 13b, and 13c are individually received by the three light receiving elements 9a, 9b, and 9c arranged in the same plane. After processing by the circuit, it is output to the document size discriminating means of the electronic copy apparatus 40. In addition, the document size discriminating means judges the presence or absence of the document at each light-transmitting position based on the output signal of the multi-beam sensor 42, and determines the size of the document 44 placed on the glass plate 41. .

(Moving body detection device)

Fig. 15A is a diagram showing an example of a moving object detection apparatus using the multi-beam sensor of the present invention, showing an entrance / exit room management system or an automatic ticket gate using the multi-beam sensor as a sensor for detecting a human body. A plurality of multi-beam sensors 66 are provided on the side surface of the moving object detecting device 65 in contact with the passage, and the detection points 27a, 27b, and 27c of each of the multi-beam sensors 66 depend on the passing direction of the person. It is arranged at almost regular intervals. As a result, as shown in Fig. 15B, from each of the light receiving elements 29a, 29b, 29c of the multi-beam sensor 66 corresponding to each of the detection points 27a, 27b, 27c arranged in a line. Outputs a signal slightly off timing. However, by monitoring the output signals from the light receiving elements 29a, 29b, 29c of each of the multi-beam sensors 65, it is possible to detect the moving speed and the moving direction of the person passing through. Since the number of sensors may be small compared to the case where sensors can be individually provided for each detection point, internal wiring of a host device such as an automatic ticket gate becomes easy. In addition, the space for mounting the sensor becomes small. Since the multi-beam sensor detects multiple points with one sensor, it is possible to detect the moving speed and the moving direction of a person passing through even one sensor. When a microcomputer system that realizes such a function is combined with a multi-beam sensor, the amount of information to be transmitted from each multi-beam sensor to a signal processing unit of a host device such as an automatic ticket gate decreases, so that such signal transmission and host device Signal processing in the signal processing section is simplified. The host apparatus does not necessarily need to use a plurality of multi-beam sensors. If the detection range is not wide, it is sufficient to use one multi-beam sensor.

Although the reflected light from a person is detected in FIG. 15, although the retroreflective member is provided before each beam is projected, the reflected light from the retroreflective member is detected when there is no person, and the reflected light is shielded when there is a person. good. In this case, the state of light reception and non-light reception in the signal waveform of FIG. 15B is reversed. As the retroreflective member, a retroreflective tape composed of a reflective surface and beads fixed before, and a retroreflective plate in which a small corner cube is assembled are known.

The configuration of the moving object detecting apparatus described above is not limited to the detection of the human body but can be applied to the detection of the moving object in general.

[Effects of the Invention]

The multi-beam sensor of the present invention can also be used as a sensor for detecting a human body having a wide viewing angle. The multi-beam sensor 66 of the present invention is attached to an ATM (automatic teller machine) 67 used in a financial institution or the like as shown in FIG. 16, or to a personal computer 68 as shown in FIG. Or when attached to an automatic machine such as an automatic plate-man machine, or an OA device such as a copier, a human body detection device capable of detecting the user's approach over a wide range (up to 70 ° in the direction of the 0th diffraction light and the ± 1st diffraction light). It can be used as a sensor.

Claims (9)

A multi-beam sensor having a light-emitting unit for emitting a plurality of light beams in different directions of space and a plurality of light-receiving elements for individually receiving each reflected light beam reflected by the object, wherein the optical axis of each reflected light beam reflected from the object An optical axis converting element for converting the optical axes to be substantially parallel to each other; And an imaging optical element and a light receiving element arranged on an optical axis of each of the reflected light beams provided in parallel with the optical axis converting element. The multi-beam sensor according to claim 2, wherein the optical axis changing element changes the optical axis direction of one reflected light beam by one or two prisms. The multi-beam sensor according to claim 1, wherein the optical axis converting element and the plurality of imaging optical elements are integrally formed. The multi-beam sensor according to claim 1, wherein the optical axis converting element or the imaging optical element is formed in a case accommodating the light receiving element. A multi-beam sensor of claim 1 arranged to emit a plurality of light beams toward the original glass; And means for discriminating the size of the document based on detection signals output from the respective light receiving elements of the multi-beam sensor. A light transmitting unit configured to emit a plurality of light beams in different directions of space; A plurality of light receiving elements that individually receive each reflected light beam by the human body; And an imaging optical element for guiding each of the reflected light beams to the corresponding light receiving element. The human body detecting device according to claim 6, wherein the light transmitting unit includes a light emitting element and light beam splitting means for dividing the emitted light of the light emitting element into a plurality of light beams so that at least a part of the divided light beams are deflected. Multi-beam sensor. A light emitting part which emits in a different direction of space according to a moving direction of an object to detect a plurality of light beams; A plurality of light receiving elements for individually receiving each reflected light beam reflected by an object to be detected; An optical element for imaging the reflected light beams to the corresponding light receiving elements, the signal being used in an apparatus for detecting movement of an object according to a difference in timing of the output of each light receiving element, Multi-beam sensor for moving object detection with output. 9. The moving apparatus of claim 8, wherein the light transmitting unit includes a light emitting element and a light beam splitting means for dividing the emitted light of the light emitting element into a plurality of light beams so that at least a part of the divided light beams are deflected. Multi-beam sensor for object detection. ※ Note: The disclosure is based on the initial application.