Measurement device and elevator system

Abstract

To measure the position and the rate of an elevator cage accurately and with a high robustness regardless of change of the state of a stationary structure of a measurement target.SOLUTION: In a measurement device 110, a radiation unit 210 has a light source 310 for emitting light and an image formation element (an image formation element 311) which can change the path of light emitted from the light source 310. Light emitted from the light source 310 through an image formation element in the radiation unit 210 enters a stationary structure (a guide rail 140) in a direction practically perpendicular to the direction of moving of the elevator cage 120.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a measuring device and an elevator system, and is suitable for application to a measuring device and an elevator system that calculate information related to the movement of an elevator.

Background Art

[0002] Conventionally, in an elevator having a car (hereinafter referred to as "elevator car" or "car") as a moving body, a governor rope has been used as a safety device for monitoring the position, speed, etc. of the elevator car. In recent years, as a device to replace the governor rope, a sensor (hereinafter referred to as "position and speed sensor") that non-contact measures the position and speed of the elevator car in a non-contact manner is known.

[0003] For example, Patent Document 1 discloses an optical position and speed sensor that photographs a structure existing in a hoistway by an image sensor installed on an elevator car and measures the position and speed of the elevator car. In the case of a non-contact measuring device such as the position and speed sensor disclosed in Patent Document 1, a long structure such as a governor rope is not required, so there is an effect that the installability and maintainability are improved. Further, there is also an effect that a measurement error due to slippage does not occur.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The optical sensor disclosed in Patent Document 1 uses a stationary structure in the hoistway, such as a guide rail, as the subject. However, due to the accumulation of dirt, rust adhesion, deterioration of oil droplets, etc., the light absorption rate of the stationary structure can change over time. Also, when the elevator adopts a shoe-type car fixing method, since lubricating oil is used to reduce friction with the guide rail, the light absorption rate of the guide rail changes more easily compared to when the roller-type car fixing method is adopted. As a result, when imaging a stationary structure (such as a guide rail) with an optical sensor, the amount of received light decreases compared to when it was newly installed, and a sufficient signal-to-noise ratio (S / N ratio) cannot be obtained, which has contributed to a decrease in the measurement accuracy and robustness of the measuring device for measuring the position and speed of the car.

[0006] The present invention has been made in consideration of the above points, and aims to propose a measuring device and an elevator system that can measure the position and speed of an elevator car with high precision and high robustness, regardless of changes in the state of the stationary structure (such as a guide rail) to be measured, and enable the optical sensor to obtain a sufficient amount of received light.

Means for Solving the Problems

[0007] In order to solve such problems, in the present invention, there is provided a measuring device installed in an elevator car moving in a hoistway, for measuring the moving distance or speed of the elevator car, the measuring device including: an irradiation unit that irradiates light onto a stationary structure arranged along the moving direction of the elevator car in the hoistway; an imaging unit that condenses scattered light from the stationary structure, which is caused by the light irradiated onto the stationary structure by the irradiation unit, onto an imaging surface; an imaging unit that captures the optical signal of the scattered light condensed by the imaging unit, converts it into an electrical signal, and performs imaging; and a measuring unit that measures the moving distance or speed of the elevator car based on the electrical signal converted by the imaging unit. The irradiation unit includes a light source that emits light and an imaging element that can change the optical path of the light emitted from the light source. The light emitted from the light source via the imaging element in the irradiation unit is incident on the stationary structure in a direction substantially perpendicular to the moving direction of the elevator car. A measuring device is provided with such a configuration.

[0008] In order to solve such problems, in the present invention, there is provided an elevator system including: an elevator car moving in a hoistway; a guide rail arranged along the moving direction of the elevator car in the hoistway; an elevator control unit that controls the operation of the elevator car; and a measuring device installed in the elevator car for measuring at least one of the moving distance or speed of the elevator car. The measuring device includes: an irradiation unit that irradiates light onto the guide rail; an imaging unit that condenses scattered light from the guide rail, which is caused by the light irradiated onto the guide rail by the irradiation unit, onto an imaging surface; an imaging unit that captures the optical signal of the scattered light condensed by the imaging unit, converts it into an electrical signal, and performs imaging; and a measuring unit that measures the moving distance or speed of the elevator car based on the electrical signal converted by the imaging unit. The irradiation unit includes a light source that emits light and an imaging element that can change the optical path of the light emitted from the light source. The light emitted from the light source via the imaging element in the irradiation unit is incident on the guide rail in a direction substantially perpendicular to the moving direction of the elevator car. An elevator system is provided with such a configuration.

Advantages of the Invention

[0009] According to the present invention, the position and velocity of the elevator car can be measured with high precision and high robustness regardless of changes in the state of the stationary structure to be measured.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0012] In each embodiment of the present invention described in detail below, in a measuring device that measures information related to the movement of a moving body (such as position, moving distance, speed, or acceleration) quickly and with high precision using a measuring unit (irradiating unit, imaging unit, and imaging unit), and in an elevator system or the like, even when a stationary structure (guide rail) to be measured has a luminance pattern (reflection / scattering luminance pattern) in which an image formed by light diffusely reflected by the stationary structure (scattered light) has a size finer than the pixels of an optical sensor, a technique for measuring the position and speed of an elevator car with high precision and high robustness based on the imaging result of the scattered light reflected by the stationary structure will be described. However, the present invention is not limited to the embodiments described below.

[0013] The measuring device according to each embodiment of the present invention described in detail below is placed at a predetermined installation position of an elevator car and measures information related to the movement of the elevator car (specifically, at least any one of the position (moving distance), speed, acceleration, or vibration of the elevator car) along a traveling path (moving path) that guides the elevator car. For example, in response to a gate signal generated by a control unit, the measuring device irradiates (transmits) light from an irradiating unit toward the surface of a stationary structure (such as a guide rail or the inner wall surface of a moving path) that has artificial polishing scratches as a subject from the moving body. Then, the measuring device makes the light reflected from the surface of the stationary structure (light that can include specularly reflected light and diffusely reflected light, and hereinafter will be referred to as "scattered light") enter the imaging surface of the imaging unit via the imaging unit, and photoelectrically converts the optical signal into an electrical signal in the imaging unit. Then, the measuring device measures information related to the movement of the elevator car in the measuring unit based on the image generated from the converted electrical signal. Further, the measuring device transmits the information related to the movement of the elevator car to an elevator car control unit (movement control unit) that controls the operation control or safety device of the elevator car based on the information related to the movement of the elevator car. Then, the movement control unit controls the operation and safety device of the elevator car based on the information related to the movement of the elevator car calculated by the measuring device.

[0014] In this specification, "light" refers to electromagnetic waves, specifically, it may be any of microwaves, terahertz waves, infrared rays, ultraviolet rays, X-rays, etc., in addition to visible light.

[0015] In the following description, when describing the same type of elements without distinction, the common part (the part excluding the branch number) of the reference signs including the branch number is used, and when distinguishing and describing the same type of elements, reference signs including the branch number may be used. For example, when describing the measuring device without particular distinction, it is described as "measuring device 110", whereas when distinguishing and describing each measuring device 110, it may be described as "measuring device 110-a", "measuring device 110-b", etc.

[0016] (1) First Embodiment (1-1) Configuration of Elevator System 10 FIG. 1 is a diagram showing a configuration example of an elevator system 10 according to the first embodiment of the present invention. The first embodiment is an embodiment showing concepts common to each embodiment of the present invention, and in the description of other embodiments (the second to seventh embodiments) described later, the detailed description of the configuration common to the first embodiment is omitted. In FIG. 1, virtual planes and axes for explaining the arrangement relationship are shown by dotted lines.

[0017] As shown in FIG. 1, the elevator system 10 includes a measuring device 110 (individually 110-a, 110-b) placed on the upper part of an elevator car 120 that moves up and down in a hoistway (travel path of a moving body) of a building (not shown). The elevator system 10 includes, in addition to the measuring device 110, components of the elevator car 120, an elevator control unit 130, and guide rails 140 (individually 140-a, 140-b), and at least any one of these components may be included in the measuring device 110.

[0018] The measuring device 110 outputs signal information (for example, signal information regarding the position, speed, acceleration, etc. of the elevator car 120) useful for controlling the operation of the elevator car 120 to the elevator control unit 130. Note that the location where the measuring device 110 is disposed is not limited to the upper part of the elevator car 120, and it may be disposed, for example, on the side surface or the lower part of the elevator car 120 (details will be described later). Further, the measuring device 110 shown in FIG. 1 has a redundant configuration by being duplicated with the measuring device 110-a and the measuring device 110-b. However, the configuration of the measuring device 110 according to the present embodiment is not limited to the duplicated configuration, and may be a single-system configuration without redundancy, or may be a redundant configuration with triple or more redundancy.

[0019] The elevator control unit 130 uses the signal information output from the measuring device 110 to control the operation of the elevator car 120 and the control of safety devices.

[0020] The guide rail 140 is an example of a stationary structure that serves as a reference when measuring the relative distance and angle of the measuring device 110, and is disposed in the hoistway. The guide rail 140 is disposed along the moving direction of the moving body (the y-axis direction in FIG. 1) in the hoistway, contacts the guide roller of the elevator car 120, and supports the movement of the moving body (the elevator car 120).

[0021] In the following description, a coordinate system is used to indicate the optical axis direction and the illumination direction of the measuring device 110. Specifically, as shown in FIG. 1, a coordinate system is defined with the moving direction of the moving body as the y-axis direction, the direction perpendicular to the imaging surface (the top surface of the convex portion of the guide rail 140 in FIG. 1) as the z-axis direction, and the direction perpendicular to both the y-axis and the z-axis as the x-axis direction. Note that, unless otherwise specified, the notations of the x-direction, the y-direction, and the z-direction may be considered synonymous with the x-axis direction, the y-axis direction, and the z-axis direction.

[0022] FIG. 2 is a diagram showing an example of the internal configuration of the measuring device 110. As shown in FIG. 2, the measuring device 110 includes an irradiation unit 210, an imaging unit 220, an imaging unit 230, and a measuring unit 240. In FIG. 2, the optical path is indicated by a dashed line with an arrow, and the path of the electrical signal is indicated by a solid line with an arrow.

[0023] The irradiation unit 210 has a light source and is arranged to irradiate light toward the surface of the guide rail 140, which is the subject, although details will be described later with reference to FIGS. 3 to 21. As the light source of the irradiation unit 210, a temporally and spatially incoherent light source such as an LED (Light Emitting Diode) or a halogen lamp may be used, or a temporally and spatially coherent light source such as a laser light source may be used. Further, a plurality of irradiation units 210 may be provided to irradiate the guide rail 140 with light from, for example, both the left and right directions.

[0024] The imaging unit 220 is configured as an optical system that forms an image of the scattered light, which is the light emitted from the irradiation unit 210 and scattered by the surface of the guide rail 140, on the imaging surface of the imaging unit 230. As the imaging unit 220, for example, a single lens made of glass or resin, a plurality of lens groups, or an imaging optical element such as a concave mirror can be used. The imaging surface of the imaging unit 230 is composed of a plurality of pixels. Then, the imaging unit 220 outputs an optical signal indicating the luminance distribution of the light that forms an image on the imaging surface including a plurality of pixels to the imaging unit 230.

[0025] The imaging unit 230 converts an optical signal received from the imaging unit 220 (the optical signal indicating the scattered luminance distribution on the surface of the guide rail 140), which is an optical signal formed on an imaging surface including a plurality of pixels, into an electrical signal corresponding to the luminance of the pixels, and synchronizes the converted electrical signal with a timing signal indicating the start time and end time of imaging transmitted from the measurement unit 240, and then transmits it to the measurement unit 240 as an image signal. For the imaging unit 230, for example, a CCD (Charge Coupled Device) image sensor, a CMOS (Complementary Metal Oxide Semiconductor) image sensor, or the like can be used. Further, the imaging unit 230 may be a two-dimensional area sensor, or may be a one-dimensional line sensor having a spatial resolution function in the elevating direction of the elevator car 120.

[0026] Note that the measuring device 110 may be provided with a wavelength selection filter such as a band-pass filter in the path of the emitted light from the irradiation unit 210 and its scattered light, other than the imaging unit 220, to remove external light other than the desired wavelength. Further, the measuring device 110 may be provided with a window material or the like in the path of the incident light and the scattered light for the purpose of protecting the measuring device 110 so that dust, dirt, etc. do not enter the inside.

[0027] The measurement unit 240 performs image processing on the image signal received from the imaging unit 230 (the electrical signal obtained by converting the optical signal formed on the imaging surface), and based on the imaging image generated by the image processing, performs processing such as pattern matching between time-series imaging images, thereby calculating information related to the movement of the elevator car 120 (specifically, at least one of the measurement results of the moving distance (amount of movement) or speed of the elevator car 120, hereinafter referred to as car movement-related information), and transmits this information to the elevator control unit 130.

[0028] Specifically, the measurement unit 240 described above may be composed of an information processing and storage medium such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or a microcontroller, or may be composed of a logic circuit element such as an FPGA (Field-Programmable Gate Array). The measurement unit 240 converts the basket movement-related information according to a communication protocol (for example, protocols such as CAN (Controller Area Network) communication and USB (Universal Serial Bus) communication) that can be received by the elevator control unit 130, and outputs the converted signal information to the elevator control unit 130. Note that the output method to the elevator control unit 130 may be a connector for connecting an electric cable or an antenna for wireless communication.

[0029] (1-2) Basic Configuration of Irradiation Unit 210 Hereinafter, the configuration of the irradiation unit 210 will be described in detail.

[0030] FIG. 3 is a top view showing the positional relationship between the irradiation unit 210 and the imaging unit 220 according to the first embodiment and the guide rail 140. In FIG. 3, the optical path is indicated by a dashed line with an arrow, and virtual planes and axes for explaining the arrangement relationship are indicated by dotted lines.

[0031] As shown in FIG. 3, the irradiation unit 210 includes a light source 310 and an imaging optical element 311.

[0032] The light source 310 is a light source for irradiating the irradiation unit 210 with a stationary structure (hereinafter, the guide rail 140). It is arranged above a plane 320 that is perpendicular to the moving direction of the elevator car 120 (parallel to the xz plane) and includes the optical axis of the imaging unit 220, and irradiates light rays L330 (L330-a, L330-b, L330-c) toward the imaging optical element 311.

[0033] The imaging optical element 311 is an optical element that changes the optical path of the light emitted from the light source 310 by refraction or reflection so that the irradiation unit 210 irradiates the guide rail 140 at a "suitable angle".

[0034] Here, the irradiation at a "suitable angle" with respect to the guide rail 140 means irradiating the guide rail 140 "perpendicularly" with respect to the moving direction of the elevator car 120. In other words, in terms of the coordinate system, it means irradiating the guide rail 140 with a light beam parallel to the xz plane. Although details will be described later, regarding being "perpendicular" (parallel to the xz plane) with respect to the moving direction of the elevator car 120, in the present invention, the angle formed does not necessarily have to be exactly 90 degrees (right angle), and the light beam group may have a spread within a predetermined allowable range. When expressing strictly including such a spread within the allowable range, it can be expressed as "substantially perpendicular" (substantially parallel to the xz plane) with respect to the moving direction of the elevator car 120. Further, since the moving direction of the elevator car 120 as viewed from above and the moving direction of the guide rail 140 as viewed from the measuring device 110 mounted on the elevator car 120 are in exactly opposite directions, regarding the above definition of the "suitable angle", it is synonymous to replace the "moving direction of the elevator car 120" with the "moving direction of the guide rail 140 as viewed from the elevator car 120 (or the measuring device 110)".

[0035] In FIG. 3, as a representative example of the imaging optical element 311, an imaging optical element using a single lens is used. However, as will be described in each of the embodiments below, an imaging optical element using a plurality of lens groups (for example, the imaging optical elements 1422, 1423, 1424 shown in FIG. 16), an imaging optical element using an anisotropic lens having different curvatures in the vertical and horizontal directions (for example, the imaging optical element 1622 shown in FIG. 18, etc.), or a reflective imaging optical element such as a concave mirror (for example, the imaging optical element 1722 shown in FIG. 20) can also be used.

[0036] In FIG. 3, the optical axis (not shown) of the imaging optical element 311 is located on the plane 320, and the light ray L330 emitted from the light source 310 is refracted by the imaging optical element 311 to become light rays L340 (L340-a, L340-b, L340-c), and is irradiated toward the guide rail 140. The refracted light ray L340 is diffused and reflected by the guide rail 140, and the diffused reflected light rays L350 (L350-a, L350-b, L350-c) are condensed by the imaging unit 220. Then, by condensing the diffused reflected light ray L350, the imaging unit 220 forms an image of the reflection / scattering luminance pattern on the convex portion of the guide rail 140 on the light receiving surface (imaging surface) of the imaging unit 230.

[0037] FIG. 4 is a diagram for explaining the positional relationship between the irradiation unit 210 and the guide rail 140 according to the first embodiment. FIG. 4(A) is a plan view in the xz plane, and FIG. 4(B) is a side view in the yz plane. In FIGS. 4(A) and 4(B), the optical path is indicated by a dashed line with an arrow, and the principal plane 410 and the focal plane 420 of the imaging optical element 311 are indicated by dotted lines as virtual planes for explaining the arrangement relationship.

[0038] As shown in FIGS. 4(A) and 4(B), the light source 310 is arranged on the focal plane 420 of the imaging optical element 311 (that is, on a plane including the focal point of the imaging optical element 311 and perpendicular to the optical axis of the imaging optical element 311). As described above with reference to FIG. 3, the light source 310 is also located on the plane 320 parallel to the xz plane and including the optical axis of the imaging unit 220. Therefore, the light source 310 is arranged on the straight line where the plane 320 and the focal plane 420 intersect. Note that "arranged on the focal plane" also includes being arranged in the vicinity of the focal plane (that is, on the same or substantially the same plane as the focal plane). A reasonable allowable range for the vicinity is, for example, "θ" in Equation 1 described later. y ".

[0039] As described above, by arranging the light source 310 on the focal plane 420 of the imaging optical element 311, the optical path of the light beam L330 emitted from the light source 310 is changed by the imaging optical element 311 and becomes a light beam L340 of a parallel light beam group that forms a direction perpendicular (or substantially perpendicular) to the moving direction of the elevator car 120, and enters the guide rail 140.

[0040] Next, the effects obtained by the measuring device 110 according to the present embodiment having the above-described configuration will be described with reference to FIGS. 5 to 8.

[0041] FIG. 5 is a conceptual diagram showing the light distribution characteristics of the diffuse reflected light in the guide rail 140. FIG. 5(A) is a plan view in the xz plane, and FIG. 5(B) is a side view in the yz plane. In FIG. 5, the optical path is indicated by a broken line with an arrow, and the principal plane 410 and the focal plane 420 of the imaging optical element 311 are indicated by dotted lines as virtual planes for explaining the arrangement relationship.

[0042] Since the guide rail 140 is polished along the y-axis, which is the car moving direction, the direction of the polishing scratches is also engraved along the y-axis. In addition, the dirt adhering over time extends along the moving direction y-axis as the elevator car 120 travels.

[0043] As a result, when the light beam L510 incident on the guide rail 140 from the lateral direction (that is, the direction parallel to the xz plane) is scattered by the guide rail 140, as shown in the xz-plane light distribution L520 of FIG. 5(A), it is scattered over a wide range in the xz plane. That is, not only in the direction of the specularly reflected light of the light beam L510 with respect to the guide rail 140 surface, but also light is widely scattered around it.

[0044] On the other hand, when the light beam L540 incident on the guide rail 140 from the longitudinal direction (that is, the direction parallel to the yz plane) is scattered by the guide rail 140, as shown in the yz-plane light distribution L530 of FIG. 5(B), it is scattered only in a narrow range in the yz plane. That is, light is strongly scattered only in the direction of the specularly reflected light of the light beam L510 with respect to the guide rail 140 surface.

[0045] FIG. 6 is a diagram for explaining the usefulness of the imaging optical element 311 in the irradiation unit 210. In FIG. 6, for comparative explanation with the irradiation unit 210 shown in FIG. 3, an irradiation unit 210A having only the light source 310 without the imaging optical element 311 is assumed, and an example of a plan view showing the positional relationship between the irradiation unit 210A, the imaging unit 220, and the guide rail 140 is shown. Note that the positional relationship of each configuration shown in FIG. 6 is the same as that in FIG. 3 except that the irradiation unit 210 shown in FIG. 3 has become the irradiation unit 210A (in other words, the imaging optical element 311 is not arranged). Also, regarding the optical path of the light irradiated from the light source 310 in FIG. 6, different reference numerals are used from those in FIG. 3.

[0046] As shown in FIG. 6, in the case of the irradiation unit 210A that does not include the imaging optical element 311, the light rays L610 (L610-a, L610-b, L610-c) emitted from the light source 310 are not changed in the optical path in a direction perpendicular (or substantially perpendicular) to the moving direction of the elevator car 120 by the imaging optical element 311 as in the irradiation unit 210, and thus enter the guide rail 140 while being inclined in the vertical direction. That is, the incident direction of the light ray L610 irradiating the guide rail 140 includes a y component. As described with reference to FIG. 5, since the light distribution in the yz plane of the guide rail 140 is narrow, the light ray L610 is strongly scattered only in the direction of the specular reflection light. As a result, the diffusely reflected light rays L620 from the guide rail 140 propagate in an oblique direction, and the diffusely reflected light rays L620 that have advanced outside the field of view end of the imaging unit 220, such as the diffusely reflected light rays L620-a and L620-c, do not enter the imaging unit 220 and cannot be focused on the imaging unit 230. As a result, within the field of view of the imaging unit 220, the intensity of the light rays (diffusely reflected light rays L620) focused by the imaging unit 220 becomes non-uniform, and there is a possibility that the imaging unit 230 cannot obtain a photographed image with sufficient contrast.

[0047] On the other hand, in the case of the irradiation unit 210 shown in FIG. 3, as described above, the light beam L330 emitted from the light source 310 becomes a light beam L340 parallel (or substantially parallel) to the xz plane by the imaging optical element 311 and irradiates the guide rail 140. Since this light beam L340 does not include a y component, the diffusely reflected light beam L350 by the guide rail 140 also does not include a y component. Further, as described with reference to FIG. 5, since the light distribution in the xz plane of the guide rail 140 is wide, the diffusely reflected light beam L350 is widely distributed in a plane parallel to the xz plane. As a result, within the field of view of the imaging unit 220, the intensity of the light beam (diffusely reflected light beam L350) collected by the imaging unit 220 becomes uniform.

[0048] FIGS. 7 and 8 are conceptual diagrams (Part 1, Part 2) showing an example of the reflection / scattering luminance pattern imaged on the light receiving surface of the imaging unit 230. The reflection / scattering luminance pattern 700 shown in FIG. 7 is an example of the reflection / scattering luminance pattern by the diffusely reflected light beam L620 of the guide rail 140 with respect to the irradiation light from the irradiation unit 210A not including the imaging optical element 311 in the configuration exemplified in FIG. 6. The reflection / scattering luminance pattern 800 shown in FIG. 8 is an example of the reflection / scattering luminance pattern by the diffusely reflected light beam L350 of the guide rail 140 with respect to the irradiation light from the irradiation unit 210 having the imaging optical element 311 in the configuration according to the present embodiment exemplified in FIG. 3.

[0049] As in the reflection / scattering luminance pattern 700 shown in FIG. 7, in the case of the irradiation unit 210A that does not include the imaging optical element 311, the intensity of the reflected light and the scattered light becomes strong (the reflection / scattering luminance pattern becomes bright) only in the region 720 at the center of the field of view of the imaging unit 220. And in the regions of the field-of-view edges 710 and 730, since the diffusely reflected light rays L620 (for example, the diffusely reflected light rays L620-a and L620-c shown in FIG. 6) do not enter the imaging unit 220, the reflection / scattering luminance pattern becomes dark, and it can be seen that a pattern of unevenness cannot be obtained with sufficient contrast. When the reflection / scattering luminance pattern becomes like 800, in order to measure information related to the movement of the elevator car 120 with sufficient accuracy in the measurement unit 240, it is necessary to perform light collection that can reinforce the dark part of the reflection / scattering luminance pattern. As a specific solution, for example, it is necessary to arrange the light sources 310 side by side in the y direction in the irradiation unit 210A. However, if such a configuration is adopted, not only does the cost increase due to the addition of the light sources 310, but it may also be necessary to finely adjust the positions of the light sources 310 arranged in the y direction in order to make the intensity of the reflected light and the scattered light to be collected uniform.

[0050] On the other hand, as in the reflection / scattering luminance pattern 800 shown in FIG. 8, in the case of the irradiation unit 210 according to the present embodiment that includes the imaging optical element 311, since the guide rail 140 can be irradiated with uniform light distribution characteristics in the y direction, the reflection / scattering luminance pattern can similarly obtain a pattern of unevenness with a uniform distribution particularly in the y direction (the vertical direction in the drawing). As a result, it becomes possible to measure information related to the movement of the elevator car 120 with sufficient accuracy in the measurement unit 240.

[0051] That is, by adopting the configuration and arrangement of the irradiation unit 210 shown in FIG. 3 and the like, the measurement device 110 according to the present embodiment can refract the light distribution of the light beam L330 emitted from the irradiation unit 210 using the imaging optical element 311 so as to be perpendicular to the moving direction (y direction) of the elevator car 120 (light beam L340), irradiate the guide rail 140 with uniform light distribution characteristics in the moving direction of the elevator car 120, and uniformly and sufficiently condense the diffused reflected light beam L350 within the field of view of the imaging unit 220. Thus, it is possible to obtain a captured image with sufficient contrast without increasing the number of light sources 310.

[0052] Regarding applying a light beam that irradiates the guide rail 140 in a direction "perpendicular" to the moving direction of the elevator car 120, in the present invention, the angle formed by the light beam with respect to the guide rail 140 does not necessarily have to be exactly 90 degrees (right angle), and it can include the "vicinity" within a predetermined allowable range centered on 90 degrees (that is, it may be approximately perpendicular). Hereinafter, the allowable range related to the spread of such a light beam group will be described in detail.

[0053] FIG. 9 is a diagram for explaining the allowable range of the spread of the beam of parallel light (parallel light beam) required when collimating the light beam output from the irradiation unit 210. In FIG. 9, the optical path is indicated by a broken line with an arrow, and the virtual planes and axes for explaining the arrangement relationship are indicated by dotted lines. Also, for simplicity of explanation, as the configuration of the imaging unit 220, an imaging optical element 810 composed of a single condenser lens and an imaging unit 220 composed of a diaphragm 820 are used, but the configuration of the imaging unit 220 is not limited to this.

[0054] As described with reference to FIG. 6, as a cause for the imaging unit 230 not being able to obtain a captured image with sufficient contrast, it can be mentioned that the light beam incident on the edge of the field of view of the imaging unit 220 is diffusely reflected outside the imaging unit 220 and is not detected by the imaging unit 230. To understand such an event in more depth, FIG. 9 is used to explain the range within which the imaging unit 220 can collect the diffusely reflected light from the guide rail 140.

[0055] As shown in FIG. 9, the imaging unit 220 includes an imaging optical element 810 (as described above, a single condenser lens is used in this example) and a diaphragm 820. Among the diffusely reflected light by the guide rail 140, the light that can be condensed by the imaging unit 220 is light rays that are refracted by the imaging optical element 810, which is a condenser lens, and can pass through the diaphragm 820. As shown in FIG. 9, the angle θ formed by the light rays (peripheral light rays) passing through the edge of the diaphragm 820 and the guide rail 140 th is defined as the divergence angle θ of the beam (light rays) in the y direction y such that |θ y | ≤ θ th Only the light rays that satisfy this relationship can pass through the diaphragm 820.

[0056] Here, θ th is expressed as θ th = asin(NA / n) by using the numerical aperture NA of the imaging unit 220 and the refractive index n of the medium between the guide rail 140 and the imaging unit 220. Therefore, the allowable range of the divergence angle θ of the beam in the y-axis direction of the light emitted from the irradiation unit 210 satisfies the condition shown in Equation 1 below. y

Equation

[0057] Specifically, for example, when the numerical aperture NA of the imaging unit 220 is 0.1 and only air (refractive index n = 1.0) exists between the guide rail 140 and the imaging unit 220, in order for the light emitted from the irradiation unit 210 to be sufficiently incident on the imaging unit 220, from the result of calculating Equation 1, the divergence angle θ of the beam in the y direction of the diffusely reflected light by the guide rail 140 y should be designed to be 5.8 degrees or less for the internal arrangement within the irradiation unit 210.

[0058] As described above, in the measuring device 110 according to the first embodiment and the elevator system 10 including the measuring device 110, the measuring device 110 irradiates the guide rail 140, which is a stationary structure, and captures an image of the scattered light diffusely reflected therefrom, and measures signal information (for example, signal information regarding the position, speed, or acceleration of the elevator car 120, etc.) useful for controlling the operation of the elevator car 120. At this time, the spread angle θ in the y-axis direction, which is directed in a direction perpendicular to the moving direction of the elevator car 120 th The irradiation unit 210 is configured such that a light beam having an angle of spread θ in the y-axis direction, which is directed in a direction perpendicular to the moving direction of the elevator car 120, and is equal to or less than asin(NA / n) is irradiated from the measuring device 110 (NA is the numerical aperture of the imaging unit 220 in the measuring device 110, and n is the refractive index of the medium between the guide rail 140, which is a stationary structure, and the imaging unit 220). According to such a measuring device 110, since the imaging unit 230 can acquire an imaging image with a uniform light reception amount as a whole, signal information useful for controlling the operation of the elevator car 120 can be measured without degrading the accuracy. Such an effect can also be obtained in other embodiments described later.

[0059] In each of the following embodiments, a specific irradiation unit that realizes the concept of the irradiation unit 210 described in the first embodiment will be described according to various basic configurations. The irradiation units shown in the following embodiments may be regarded as one example of realizing the irradiation unit 210 in the first embodiment, and each of the drawings (FIGS. 1 to 9) used in the description of the first embodiment is applicable to all of the embodiments in principle.

[0060] (2) Second Embodiment FIG. 10 is a diagram showing the positional relationship of each part in the measuring device 910 according to the second embodiment of the present invention. The diagram shown in FIG. 10 is a plan view in the xz plane. In FIG. 10, the optical path is shown by a broken line with an arrow, and virtual planes and axes for explaining the arrangement relationship are shown by dotted lines.

[0061] The measurement device 910 according to the second embodiment includes a plurality of irradiation units 920 (irradiation units 920-a and 920-b in the case of FIG. 10) as an example of the implementation of the irradiation unit 210 in the measurement device 110 according to the first embodiment. Since the configurations of the measurement device 910 other than those described above are the same as those of the measurement device 110 according to the first embodiment, detailed descriptions thereof are omitted.

[0062] The measurement device 910 according to the second embodiment is characterized in that it reduces the uneven illuminance in the x-axis direction in the captured image captured by the imaging unit 230 and realizes a measurement device that is robust against the sway in the x-axis direction of the elevator car 120.

[0063] In addition, the irradiation unit 920 included in the measurement device 910 has a plurality of redundant configurations, and is characterized in that a stronger illumination light amount can be obtained compared to the irradiation unit 210 in the measurement device 110 according to the first embodiment. Further, the irradiation unit 920 is characterized in that by driving a plurality of light sources using independent current sources, even if any one of the light sources fails, the light irradiation intensity does not completely become zero, and the performance can be maintained to a certain extent.

[0064] As shown in FIG. 10, the irradiation unit 920 independently includes a combination of a light source 921 and an imaging optical element 922 on the left and right sides of the imaging unit 220 (the irradiation unit 920-a and the irradiation unit 920-b have independent configurations). More specifically, the irradiation unit 920-a includes a light source 921-a and an imaging optical element 922-a, and the irradiation unit 920-b includes a light source 921-b and an imaging optical element 922-b.

[0065] The irradiation units 920-a and 920-b each irradiate light toward the guide rail 140 from a direction perpendicular to the moving direction (y-axis direction) of the elevator car 120. And similar to the irradiation unit 210 according to the first embodiment, the position of the focal plane of the imaging optical element 922 corresponding to each set of light sources 921 is arranged such that the spread angle of the light irradiated from each of the irradiation units 920-a and 920-b is equal to or less than asin(NA / n).

[0066] The irradiation units 920-a and 920-b are arranged symmetrically with respect to the imaging unit 220 (which may be replaced by the guide rail 140). Since the light sources 921 of the irradiation units 920-a and 920-b arranged in this way irradiate light toward the guide rail 140, the images captured by the imaging unit 230 (not shown in FIG. 10) are also symmetrical about the left and right. As a result, the measuring device 910 can capture more uniform images not only in the y-axis direction but also in the x-axis direction.

[0067] FIG. 11 is a diagram showing another configuration example of the measuring device 910 according to the second embodiment. In FIG. 11, the optical path is indicated by a broken line with an arrow, and virtual planes and axes for explaining the arrangement relationship are indicated by dotted lines.

[0068] In the measuring device 910 shown in FIG. 11, the irradiation unit 920 includes a plurality of combinations of a light source 921 and an imaging optical element 922 independently in two directions, that is, four directions on the left and right sides of the imaging unit 220, respectively. More specifically, in the irradiation unit 920 shown in FIG. 11, irradiation units 920-c and 920-d are added outside (the side away from the imaging unit 220) the two irradiation units 920-a and 920-b shown in FIG. 10. The irradiation unit 920-c includes a light source 921-c and an imaging optical element 922-c, and the irradiation unit 920-d includes a light source 921-d and an imaging optical element 922-d. That is, the irradiation unit 920 shown in FIG. 10 has a configuration including two sets of combinations of the light source 921 and the imaging optical element 922, while the irradiation unit 920 shown in FIG. 11 has a configuration including four sets of combinations of the light source 921 and the imaging optical element 922. And similar to the irradiation unit 210 according to the first embodiment, the position of the focal plane of the imaging optical element 922 corresponding to each set of light sources 921 is determined so that the divergence angle of the light irradiated from each of the irradiation units 920-a, 920-b, 920-c, and 920-d is equal to or less than asin(NA / n).

[0069] In the case of the configuration shown in FIG. 11, similar to the configuration shown in FIG. 10, since the light sources 921 of the respective irradiation units 920 arranged symmetrically with respect to the imaging unit 220 irradiate light toward the guide rail 140, the images captured by the imaging unit 230 are also symmetric about the y-axis. As a result, the measuring device 910 can capture a more uniform image not only in the y-axis direction but also in the x-axis direction. Further, as a difference from the configuration of FIG. 10, in the case of the configuration of FIG. 11, since light is irradiated toward the guide rail 140 at different incident angles (specifically, two incident angles), it is possible to further improve the uniformity in the x-axis direction.

[0070] In FIGS. 10 and 11, as a configuration example of the plurality of irradiation units 920 arranged in different directions in the xz plane (meaning that the angles formed with respect to the guide rail 140, which is a stationary structure, are different) to irradiate the guide rail 140, the case where there are two sets (FIG. 10) and the case where there are four sets (FIG. 11) of the combination of the light source 921 and the imaging optical element 922 included in the irradiation unit 920 are shown. However, the configuration of the irradiation unit 920 in the measuring device 910 according to the second embodiment is not limited to these two types. For example, when arranging three or more sets of the light source 921 and the imaging optical element 922 as the irradiation unit 920, it is possible to further enhance the uniformity of the light reception amount in the x-axis direction while making the light reception amount in the y-axis direction uniform by a symmetric arrangement. Note that, for the purpose of increasing the light reception amount in the x-axis direction, even if it is not symmetric, a plurality of irradiation units 920 (light source 921 and imaging optical element 922) may be arranged.

[0071] According to the measuring device 910 according to the second embodiment configured as described above, by adopting a plurality of irradiation units 920, it is possible to obtain a uniform image not only in the y-axis direction but also in the x-axis direction, and an optical system capable of robustly performing image processing against vibrations in the x direction of the elevator car 120 can be realized.

[0072] (3) Third Embodiment Figures 12 and 13 are diagrams (Part 1 and Part 2) showing the positional relationships of the respective parts in the measuring device 1110 according to the third embodiment of the present invention. The diagram shown in Figure 12 is a top view, and the diagram shown in Figure 13 is a plan view in the xz plane. In Figures 12 and 13, the optical path is indicated by a dashed line with an arrow, and virtual planes and axes for explaining the arrangement relationship are indicated by dotted lines.

[0073] The measuring device 1110 according to the third embodiment includes an irradiation unit 1120 as an example of realizing the irradiation unit 210 in the measuring device 110 according to the first embodiment. Note that since the configurations of the measuring device 1110 other than the above are the same as those of the measuring device 110 according to the first embodiment, detailed descriptions thereof are omitted.

[0074] The measuring device 1110 according to the third embodiment is characterized in that it uniformly illuminates the guide rail 140 regardless of the distance between the guide rail 140 and the measuring device 1110 along the z-axis direction, and realizes a measuring device that is robust against the sway of the elevator car 120 in the z-axis direction.

[0075] As shown in Figures 12 and 13, the irradiation unit 1120 includes a light source 1121 and an imaging optical element 1122. In the irradiation unit 1120, a plurality of light sources 1121 are arranged with respect to one imaging optical element 1122. The plurality of light sources 1121 are arranged on a straight line 1143 where a plane 1141 parallel to the xz plane including the optical axis of the imaging unit 220 intersects with the focal plane 1142 of the imaging optical element 1122. In the present embodiment, by arranging the plurality of light sources 1121 on the straight line 1143, the light beam emitted from the light source 1121 is refracted by the imaging optical element 1122 and irradiated toward the guide rail 140.

[0076] Note that the "on the straight line" such as "on the straight line 1143" does not necessarily have to exactly coincide with the straight line. When it is arranged on the straight line, it can include the case of being arranged in the vicinity of a single straight line (that is, it may be substantially on the straight line). However, when a plurality of light sources 1121 are arranged substantially on the straight line including the vicinity of the straight line 1143, it is required that the arrangement be within an allowable range such that the divergence angle of the light beam group emitted from the irradiation unit 1120 in the y-axis direction is equal to or less than asin(NA / n).

[0077] As shown in FIG. 13, the light rays emitted from a plurality of light sources 1121 (1121-a to 1121-d) enter the field of view of the imaging unit 220 at different z positions (different positions in the z direction). As a result, even if the z position of the guide rail 140 fluctuates relatively, since the light ray emitted from any one of the light sources 1121 can illuminate the guide rail 140, the imaging unit 230 can obtain an imaging image with a sufficient amount of received light via the imaging unit 220.

[0078] Hereinafter, in arranging the light source 1121 on the straight line 1143 in the present embodiment, a relational expression for calculating the position of the light source and the light distribution angle of the light ray emitted from the light source from the allowable value Δz of the required distance fluctuation is derived.

[0079] FIG. 14 is a conceptual diagram for deriving the relationship between the position Δx of a certain light source 1121-a and the allowable value Δz of the distance fluctuation between the guide rail 140 and the measuring device 910. In FIG. 12, the optical path is shown by a broken line with an arrow, and the virtual planes and axes for explaining the arrangement relationship are shown by dotted lines. For the sake of convenience of explanation, the position Δx of the light source 1121 is taken as positive in the direction in which the x coordinate is positive, and the allowable value Δz is taken as positive in the direction in which the z coordinate is positive.

[0080] Also, as shown in FIG. 14, let the intersection point of the optical axis 1144 of the imaging optical element 1122 in the irradiation unit 1120 and the optical axis 1145 of the imaging optical element (not shown) in the imaging unit 220 be O, and the angle formed be φ. φ is positive in the right-handed direction around the y-axis. Further, let the two foci of the imaging optical element 1122 be F and F' (F' is on the light source 1121 side), and let the light ray L1201 emitted from the light source 1121 parallel to the optical axis 1144 be refracted by the imaging optical element 1122, and let the point where the refracted light ray L1202 intersects the optical axis 1145 of the imaging unit 220 be P. When installing the measuring device 1110 in the elevator car 120, it is installed such that the convex portion (the surface observed by the measuring device 1110) of the guide rail 140 coincides with the point O. At this time, let the observed surface at the convex portion of the guide rail 140 after the distance variation be surface 1203, and assuming that the point P is on the surface 1203, the relationship between the position Δx of the light source 1121 and the distance variation Δz is derived. Note that the distance variation Δz occurs with respect to the point O, and Δz is measured with the positive direction of the z-coordinate as seen from the point O being positive. Also, the position Δx of the light source 1121 is measured with respect to the focus F'.

[0081] As a constant for determining the position of the irradiation unit 1120, the distance l from the principal plane of the imaging optical element 1122 to the point O is used. At this time, the distance OF between the point O and the point F is expressed by the following equation 2 using the focal length f of the imaging optical element 1122. Also, if the foot of the perpendicular dropped from the point P to the straight line OF is the point H, the distance OH is expressed by the following equation 3, the distance PH is expressed by the following equation 4. Also, since the distance FH is the value obtained by subtracting the distance OH from the distance OF, it is expressed by the following equation 5.

Equation

[0082] From the above results of equations 2 to 5, the position Δx of one light source 1121-a is selected to satisfy equation 6 using the allowable value Δz of the distance variation.

Equation

[0083] In the third embodiment, by determining the position of the light source 1121-a from the specification of the allowable value Δz of the distance variation so as to satisfy the above formula 6, it is expected that a sufficient amount of light can be obtained even if a distance variation within the allowable value occurs.

[0084] Further, it can be assumed that the distance variation occurs not only in the positive direction of the z-axis but also in the negative direction of the z-axis. Therefore, the light source can be configured to be robust against distance variation not only by setting the position of the light source 1121-a but also by arranging a plurality of light sources 1121 along the straight line 1143 as shown in FIGS. 12 and 13. Specifically, for example, when the distance variation occurs in the range of -Δz to +Δz, by arranging a plurality of light sources 1121 so that the position Δx of the light source 1121 satisfies the following formula 7, a configuration robust against distance variation in the range of -Δz to +Δz can be realized.

Equation

[0085] FIG. 15 is a conceptual diagram for deriving the light distribution angle of the light source 1121 for obtaining a uniform image within the field of view in the third embodiment. FIG. 15(A) is an overall view of the irradiation unit 1120, and FIG. 15(B) is an enlarged view of the circle 1301 shown in FIG. 15(A) in the vicinity of the plane 1203. In FIG. 15, the optical path is indicated by a broken line with an arrow, and virtual planes and axes for explaining the arrangement relationship are indicated by dotted lines.

[0086] As shown in FIG. 15, the light distribution angle of a certain light source 1121-a, that is, the half-value angle in the angular distribution of the radiant luminance, is defined as "θ" 1 / 2 ". Among the light rays in the xz plane emitted in the θ 1 / 2 direction, the light ray directed in the optical axis direction is defined as L1302. Also, let the intersection of the principal plane of the imaging optical element 1122 and the light ray L1201 be H1, and the intersection of the principal plane of the imaging optical element 1122 and the light ray L1302 be H2. Also, let the intersection of the optical axis 1144 and the plane 1203 be Q, the intersection of the plane 1203 and the light ray L1303 after the light ray L1302 is refracted by the imaging optical element 1122 be R, and the intersection of the light ray L1303 and the straight line PH be S.

[0087] Next, among the points within the field of view when observing the guide rail 140 by the imaging unit 220 and the imaging unit 230, the maximum value of the distance from the point P is defined as d, and the condition for the light source 1121-a to illuminate the surface 1203 with sufficient illuminance within the field of view is derived. For the light source 1121-a to achieve sufficient illuminance, it means being within the range of the light distribution angle, and since the light ray L1303 may enter outside the field of view of the imaging unit 220, the condition "d ≤ PR" is satisfied for the line segment PR.

[0088] Here, the light distribution angle θ of the light source 1121-a 1 / 2 can be expressed by the following formula 8, and the line segment PS can be expressed by the following formula 9.

Number

[0089] Next, focusing on the triangle PSR (△PSR) shown in FIG. 15(B), the relationship between the length of the line segment PR and the length of the line segment PS is obtained. Specifically, the angle ∠RPS is expressed by the following formula 10, the angle ∠PSR is expressed by the following formula 11, and the angle ∠PRS is expressed by the following formula 12.

Number

[0090] Then, using the above formulas 10 to 12 for the sine theorem of △PSR, the following relational expression of formula 13 is established, and when formula 13 is rearranged, it becomes formula 14.

Number

[0091] Then, using formula 14 and formula 9 to rearrange the condition "d ≤ PR", the following relational expression of formula 15 is shown for tanθ 1 / 2

Number

[0092] ​ Therefore, in the third embodiment, by selecting the light distribution angle θ of the light source 1121-a so as to satisfy Equation 15, it is possible to obtain sufficient illuminance within the field of view even with respect to the distance variation Δz. Specifically, for example, when the focal length f = 50 mm, the field of view d = 6.4 mm, the incident angle φ = 40 degrees, and the light source position Δx = 7.5 mm, as a result of calculating Equation 15, if the light distribution angle θ 1 / 2 is 5 degrees or more, sufficient illuminance can be obtained within the field of view even with respect to the distance variation. 1 / 2

[0093] The measuring device 1110 according to the third embodiment configured as described above arranges a plurality of light sources 1121 in the vicinity of a straight line 1143 where a plane 1141 including the optical axis of the imaging unit 220 parallel to the xz plane and the focal plane 1142 of the imaging optical element 1122 intersect. Thus, regardless of the distance between the guide rail 140 and the measuring device 1110 along the z-axis direction, the guide rail 140 can be uniformly illuminated, and an illumination system robust against the sway of the elevator car 120 in the z-axis direction can be realized. Further, the plurality of light sources 1121 can uniformly illuminate the guide rail 140 with respect to a desired distance variation Δz by specifying the position Δx so as to include the range specified by Equation 7. Also, by selecting the light source 1121 having the light distribution angle θ 1 / 2 specified by Equation 15, it is possible to obtain sufficient illuminance within the field of view defined by the imaging unit 220 and the imaging unit 230.

[0094] Note that, as will be described later in the fourth embodiment, the plurality of light sources 1121 do not necessarily have a physical entity, and may be constituted by, for example, a real image of another light source.

[0095] (4) Fourth Embodiment FIG. 16 is a diagram showing the positional relationship of each part in the measuring device 1410 according to the fourth embodiment of the present invention. The diagram shown in FIG. 16 is a plan view in the xz plane. In FIG. 16, the optical path is indicated by a broken line with an arrow, and virtual planes and axes for explaining the arrangement relationship are indicated by dotted lines.

[0096] The measurement device 1410 according to the fourth embodiment includes an irradiation unit 1420 as an example of one realization of the irradiation unit 210 in the measurement device 110 according to the first embodiment. Note that since the configurations of the measurement device 1410 other than those described above are the same as those of the measurement device 110 according to the first embodiment, detailed descriptions thereof are omitted.

[0097] Similar to the measurement device 1110 according to the third embodiment, the measurement device 1410 according to the fourth embodiment has a feature of uniformly illuminating the guide rail 140 regardless of the distance between the guide rail 140 and the measurement device 1410 along the z-axis direction, and realizing a measurement device that is robust against the sway of the elevator car 120 in the z-axis direction.

[0098] Further, different from the measurement device 1110 according to the third embodiment, the measurement device 1410 according to the fourth embodiment can manufacture the irradiation unit 1420 at low cost by including a single light source 1421. Also, by including a single light source 1421, the current applied to the light source 1421 can be reduced, and the power consumption can be suppressed. The arrangement of the irradiation unit 1420 in the measurement device 1410 that realizes such features will be described in detail below with reference to FIG. 16.

[0099] As shown in FIG. 16, the irradiation unit 1420 includes a single light source 1421, a first imaging optical element 1422, a second imaging optical element 1423, and a third imaging optical element 1424. For the first imaging optical element 1422 and the third imaging optical element 1424, for example, a single lens (refractive convex lens) made of glass or resin can be used, or an imaging optical element such as a plurality of lens sets or a concave mirror may be used. The second imaging optical element 1423 is an array imaging optical element (so-called microlens array) in which imaging optical elements are arranged in a matrix in the x direction.

[0100] In the irradiation unit 1420, the light beam group emitted from the light source 1421 passes through the first imaging optical element 1422 and the second imaging optical element 1423, and is imaged near the straight line where the plane (not shown) including the optical axis of the imaging unit 220 parallel to the xz plane intersects the focal plane 1425 of the third imaging optical element 1424, forming a plurality of real images 1426 arranged in an array. This array of real images 1426 can be regarded as corresponding to the plurality of light sources 1121 in the third embodiment. Then, the light beam group that forms a real image on the focal plane 1425 is refracted by the third imaging optical element 1424 and irradiated toward the guide rail 140.

[0101] Note that the real image 1426 does not necessarily have to be arranged exactly on the straight line where the plane including the optical axis of the imaging unit 220 intersects the focal plane 1425. As long as the divergence angle in the y-axis direction of the light beam group emitted from the irradiation unit 1420 is equal to or less than asin(NA / n), it may be formed (arranged) near the straight line.

[0102] In this case, the interval d array between the imaging optical elements in the array-shaped second imaging optical element 1423 array and the focal length f array of the imaging optical element are configured such that the plurality of real images 1426 satisfy the above-described equations 7 and 15. Specifically, since the real image 1426 is imaged at a position where the center of each lenslet (unit cell in the array) in the second imaging optical element 1423 is translated parallel to the optical axis of the lenslet by the focal length f array , the interval d 1 / 2 is selected so that the center of each lenslet is located within the range of equation 7. Also, since the light distribution angle θ array of the light beam emitted from the array-shaped second imaging optical element 1423 is the arctangent of the value obtained by dividing half of the interval d array by the focal length f array , it is expressed as the following equation 16. Based on the above, the focal length f 1 / 2

Equation

[0103] According to the measuring device 1410 according to the fourth embodiment configured as described above, a plurality of real images 1426 of a certain light source 1421 are arranged in an array in the vicinity of a straight line where a plane including the optical axis of the imaging unit 220 parallel to the xz plane intersects the focal plane 1425 of the imaging optical element 1424, so that the guide rail 140 can be uniformly illuminated regardless of the distance between the guide rail 140 and the measuring device 1410 along the z-axis direction, and a lighting system robust against the sway of the elevator car 120 in the z-axis direction can be realized. Further, unlike the third embodiment, by using the real images of a certain light source 1421 as a plurality of light sources, the number of physical light sources can be reduced, and the cost and power consumption of the irradiation unit 1420 can be suppressed from decreasing.

[0104] (5) Fifth Embodiment FIG. 17 is a diagram showing the positional relationship of each part in the measuring device 1510 according to the fifth embodiment of the present invention. The diagram shown in FIG. 17 is a plan view in the xz plane. In FIG. 17, the optical path is shown by a broken line with an arrow, and virtual planes and axes for explaining the arrangement relationship are shown by dotted lines.

[0105] The measuring device 1510 according to the fifth embodiment includes an irradiation unit 1520 as an example of realizing the irradiation unit 210 in the measuring device 110 according to the first embodiment. Since the configurations of the measuring device 1510 other than the above are the same as those of the measuring device 110 according to the first embodiment, detailed descriptions thereof are omitted.

[0106] Similar to the measuring device 1110 according to the third embodiment and the measuring device 1410 according to the fourth embodiment, the measuring device 1510 according to the fifth embodiment has the feature of realizing a measuring device that uniformly illuminates the guide rail 140 regardless of the distance between the guide rail 140 and the measuring device 1510 along the z-axis direction and is robust against the sway of the elevator car 120 in the z-axis direction.

[0107] Further, unlike the measurement device 1110 according to the third embodiment, the measurement device 1510 according to the fifth embodiment includes a single light source 1521, making it possible to manufacture the irradiation unit 1520 at low cost. Also, by including a single light source 1521, the current applied to the light source 1521 can be reduced, and power consumption can be suppressed.

[0108] Furthermore, the measurement device 1510 according to the fifth embodiment is different from the measurement device 1110 according to the third embodiment and the measurement device 1410 according to the fourth embodiment in that it can change the illuminance distribution more continuously with respect to distance variation. The arrangement of the irradiation unit 1520 in the measurement device 1510 that realizes such a feature will be described in detail below with reference to FIG. 17.

[0109] As shown in FIG. 17, the irradiation unit 1520 includes a light source 1521, a diffuser plate 1522, and an imaging optical element 1523. The diffuser plate 1522 is arranged in the vicinity of the straight line where a plane parallel to the xz plane (not shown) including the optical axis of the imaging unit 220 and the focal plane 1524 of the imaging optical element 1523 intersect, and diffuses the light beam emitted from the light source 1521. The light beam diffused from the diffuser plate 1522 is refracted by the imaging optical element 1523 and irradiated toward the guide rail 140.

[0110] Note that the diffuser plate 1522 does not necessarily have to be arranged "exactly coincident" with the straight line where the plane including the optical axis of the imaging unit 220 and the focal plane 1524 intersect. As long as the divergence angle in the y-axis direction of the light beam emitted from the irradiation unit 1520 is equal to or less than asin(NA / n), it may be formed (arranged) in the vicinity of the straight line. At this time, the scattering luminance distribution of the diffuser plate 1522 is selected so that its light distribution angle θ 1 / 2 satisfies Equation 15.

[0111] The measuring device 1510 according to the fifth embodiment configured as described above has a diffusion surface by the diffusion plate 1522 arranged in the vicinity of a straight line where a plane parallel to the xz plane including the optical axis of the imaging unit 220 intersects with the focal plane 1425 of the imaging optical element 1424. By this arrangement, regardless of the distance between the guide rail 140 and the measuring device 1410 along the z-axis direction, the guide rail 140 can be uniformly illuminated, and an illumination system robust against the sway of the elevator car 120 in the z-axis direction can be realized. Also, different from the third embodiment, by adopting the diffusion plate 1522 that provides a diffusion surface for diffusing the light source 1521, the number of physical light sources can be reduced, and the cost and power consumption of the irradiation unit 1520 can be suppressed. Further, on the diffusion surface by the diffusion plate 1522, since diffusion points are continuously formed (different from the discretely arranged microlenses), it is possible to change the illuminance distribution more continuously with respect to distance variation.

[0112] (6) Sixth Embodiment FIG. 18 and FIG. 19 are diagrams (Part 1, Part 2) showing the positional relationship of each part in the measuring device 1610 according to the sixth embodiment of the present invention. The diagram shown in FIG. 18 is a top view, the diagram shown in FIG. 19(A) is a plan view in the xz plane, and the diagram shown in FIG. 19(B) is a side view in the yz plane. In FIGS. 18 and 19, the optical path is indicated by a dashed line with an arrow, and virtual planes and axes for explaining the arrangement relationship are indicated by dotted lines.

[0113] The measuring device 1610 according to the sixth embodiment includes an irradiation unit 1620 as an example of realizing the irradiation unit 210 in the measuring device 110 according to the first embodiment. Since the configurations of the measuring device 1610 other than the above are the same as those of the measuring device 110 according to the first embodiment, detailed description thereof is omitted.

[0114] The measuring device 1610 according to the sixth embodiment has the feature that, regarding the spread of the light beam group irradiated from the irradiation unit 1620 toward the guide rail 140, while suppressing the spread of the light beam group in the y direction in the same manner as in the first embodiment, the spread of the light beam group is not suppressed but diffused in the xz plane, so that the guide rail 140 can be illuminated over a wider range.

[0115] As shown in FIGS. 18 and 19, the irradiation unit 1620 includes a single light source 1621 and an anisotropic imaging optical element 1622 that has a strong curvature in the y direction and different curvatures in two intersecting directions (the y direction and the xz plane direction). The imaging optical element 1622 is, for example, a cylindrical lens having a curvature in only one intersecting direction or a toroidal lens having different curvatures in two intersecting directions. In FIGS. 18 and 19, a cylindrical lens is used.

[0116] In the case of the irradiation unit 1620 shown in FIG. 18, the imaging optical element 1622, which is a cylindrical lens, is arranged so that the curvature direction is in the y direction and the direction without curvature is located in the xz plane. Then, the light source 1621 is arranged in the vicinity of the straight line 1623 where the plane 1631 including the optical axis of the imaging unit 220 parallel to the xz plane intersects the focal plane 1624 of the imaging optical element 1622 in the y direction. With such an arrangement, the light beam group emitted from the light source 1621 is strongly refracted mainly in the y direction by the imaging optical element 1622 and irradiated toward the guide rail 140, as shown in FIG. 19(B).

[0117] Note that the light source 1621 does not necessarily have to be arranged exactly coincident with the straight line 1623, and may be formed (arranged) in the vicinity of the straight line 1623 as long as the spread angle of the light beam group emitted from the irradiation unit 1620 in the y-axis direction is equal to or less than asin(NA / n).

[0118] In addition, in the present embodiment, since the imaging optical element 1622 is an anisotropic imaging optical element, the curvature in the xz plane is different from the curvature in the y direction. By making the curvature in the xz plane of this imaging optical element 1622 smaller than the curvature in the y direction, as shown in FIG. 19(B) and the like, the light rays emitted from the light source 1621 enter the guide rail 140 with relatively small refraction. For example, when the imaging optical element 1622 is a cylindrical lens, since the curvature in the xz plane is 0, the light rays incident on the imaging optical element 1622 travel straight in the direction of the xz plane and enter the guide rail 140. As a result, in the xz direction, the guide rail 140 can be irradiated over a wider range, and even when the imaging unit 220 and the imaging unit 230 have a relatively wide field of view, it is possible to obtain a sufficient amount of light within the field of view.

[0119] (7) Seventh Embodiment FIG. 20 is a diagram showing the positional relationship of each part in the measuring device 1710 according to the seventh embodiment of the present invention. Further, FIG. 21 is a side view of the irradiation unit 1720 in a plane including the y-axis. In FIGS. 20 and 21, the optical path is shown by a broken line with an arrow, and virtual planes and axes for explaining the arrangement relationship are shown by dotted lines.

[0120] The measuring device 1710 according to the seventh embodiment includes an irradiation unit 1720 as an example of the irradiation unit 210 in the measuring device 110 according to the first embodiment. Since the configurations of the measuring device 1710 other than the above are the same as those of the measuring device 110 according to the first embodiment, detailed description thereof is omitted.

[0121] The measuring device 1710 according to the seventh embodiment uses a reflective imaging optical element such as a concave mirror for the imaging optical element 1722 included in the irradiation unit 1720, thereby suppressing the influence of chromatic aberration in the imaging optical element and suppressing the wavelength dependence on the illuminance distribution even for a light source 1721 having broadband wavelength characteristics.

[0122] As shown in FIG. 20, the irradiation unit 1720 includes a light source 1721 and a reflective imaging optical element 1722. The imaging optical element 1722 is, for example, a parabolic mirror with reduced spherical aberration. In FIG. 20, as an example, an off-axis parabolic mirror is used.

[0123] The irradiation unit 1720 is configured such that the divergence angle in the y-axis direction of the light beam emitted from the light source 1721 and reflected by the imaging optical element 1722 is equal to or less than asin(NA / n). Specifically, as shown in FIG. 21, with respect to the imaging optical element 1722, which is a parabolic mirror, the light source 1721 is arranged at the focal position of the parabolic surface, and the xy plane is taken parallel to the straight line connecting the focus and the vertex of the parabolic surface, so that the divergence angle in the y-direction of the light beam reflected by the parabolic mirror of the imaging optical element 1722 can be arranged to be parallel.

[0124] Note that each of the above-described embodiments is for clearly explaining the present invention and does not limit the scope of the present invention. For example, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Also, for example, it is possible to add, delete, replace, etc. other configurations to a part of the configuration of each embodiment.

[0125] In addition, each of the above-described configurations, functions, processing units, processing means, etc. may be realized in hardware by designing part or all of them, for example, in an integrated circuit. Further, each of the above-described configurations, functions, etc. (for example, the measurement unit 240, etc.) may be realized in software by a processor interpreting and executing a program for realizing each function. Information such as programs, tables, files, etc. for realizing each function can be stored in a memory, a recording device such as a hard disk, an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, a DVD. In particular, the program may be installed from a program source into a device such as a computer. The program source may be, for example, a program distribution server or a non-transitory storage medium readable by a computer. When the program source is a program distribution server, the program distribution server includes a processor (for example, a CPU) and a non-transitory storage resource, and the storage resource may further store a distribution program and a program to be distributed. Then, by the processor of the program distribution server executing the distribution program, the processor of the program distribution server may distribute the program to be distributed to other computers. Also, in the following description, two or more programs may be realized as one program, or one program may be realized as two or more programs. In the drawings, control lines and information lines show those considered necessary for explanation, and not necessarily all control lines and information lines on the product are shown. In fact, it may be considered that almost all components are interconnected.

Explanation of Reference Numerals

[0126] 10 Elevator System 110, 910, 1110, 1410, 1510, 1610, 1710 Measuring Device 120 Elevator Car 130 Elevator Control Unit 140 Guide Rail 210, 920, 1120, 1420, 1520, 1620, 1720 Irradiation Unit 220 Imaging Unit 230 Imaging unit 240 Measurement unit 310, 921, 1121, 1421, 1521, 1621, 1721 Light sources 311, 810, 922, 1122, 1422, 1423, 1424, 1523, 1622, 1722 Imaging optical elements 700, 800 Scattering luminance patterns 820 Diaphragm 1522 Scattering plate

Claims

1. A measuring device installed in an elevator car that moves in a hoistway and measures the moving distance or speed of the elevator car, an irradiating unit that irradiates light onto a stationary structure arranged along the moving direction of the elevator car in the hoistway, an imaging unit that condenses scattered light from the stationary structure due to the light irradiated on the stationary structure by the irradiating unit onto an imaging surface, an imaging unit that captures the optical signal of the scattered light condensed by the imaging unit, converts it into an electrical signal, and performs imaging, a measuring unit that measures the moving distance or speed of the elevator car based on the electrical signal converted by the imaging unit, comprising: the irradiating unit having a light source that emits light and an imaging element that can change the optical path of the light emitted from the light source, light emitted from the light source via the imaging element in the irradiating unit enters the stationary structure in a direction substantially perpendicular to the moving direction of the elevator car, A measuring device characterized by this.

2. In order for the imaging unit to be able to uniformly condense the scattered light from the stationary structure within its field of view, the irradiating unit is arranged such that the divergence angle of the light emitted from the irradiating unit and irradiating the stationary structure in the moving direction of the elevator car falls within a predetermined range. The measuring device according to claim 1, characterized by this.

3. Let the divergence angle of the light emitted from the irradiation unit in the moving direction of the elevator car be θ ｙ when the numerical aperture of the imaging unit is NA and the refractive index of the medium between the measuring device and the stationary structure is n, |θ ｙ | ≤ asin(NA / N) ... (Equation 1) The relational expression holds. The measuring device according to claim 2, characterized by this.

4. The divergence angle of the light emitted from the irradiating unit in the moving direction of the elevator car is 5.8 degrees or less. The measuring device according to claim 1, characterized by this.

5. In the irradiating unit, the light source is arranged on the focal plane of the imaging element, the optical axis of the imaging element is arranged in a plane perpendicular to the moving direction of the elevator car. The measuring device according to claim 1, characterized by this.

6. In the irradiating unit, the imaging element is a cylindrical lens that refracts light with respect to the moving direction of the elevator car. The measuring device according to claim 1, characterized by this.

7. In the irradiating unit, the imaging element is a concave mirror. The measuring device according to claim 1, characterized by this.

8. The light source is arranged in the vicinity of the straight line where the plane perpendicular to the moving direction of the elevator car and including the optical axis of the imaging unit intersects the focal plane of the imaging element. The measuring device according to claim 1, characterized by this.

9. The irradiation unit has two or more of the light sources corresponding to one of the imaging elements. The measuring device according to claim 8, characterized in that.

10. In the irradiation unit, a light distribution angle of the light source is 5 degrees or more. The measuring device according to claim 8, characterized in that.

11. The irradiation unit further has a specific imaging element that forms an image of the light source, separately from the imaging element. An image of the light source formed by the specific imaging element is disposed on a focal plane of the imaging element. An optical axis of the imaging element is disposed in a plane perpendicular to a moving direction of the elevator car. The measuring device according to claim 1, characterized in that.

12. The specific imaging element is an array imaging element. When light from the light source passes through the specific imaging element, two or more images of the light source are disposed on the focal plane of the imaging element. The measuring device according to claim 11, characterized in that.

13. The irradiation unit has a diffusing plate that diffuses light from the light source, in front of the imaging element. The diffusing plate is disposed on the focal plane of the imaging element. The measuring device according to claim 1, characterized in that.

14. The irradiation unit has at least two or more sets of a combination of the light source and the imaging element. Light emitted from each set forms different incident angles with respect to the stationary structure. The measuring device according to claim 1, characterized in that.

15. An elevator car moving in a hoistway, A guide rail disposed along a moving direction of the elevator car in the hoistway, An elevator control unit that controls an operation of the elevator car, A measuring device installed in the elevator car that measures at least one of a moving distance or a speed of the elevator car, Comprising, The measuring device, An irradiation unit that irradiates light onto the guide rail, An imaging unit that condenses scattered light from the guide rail, due to the light irradiating the guide rail by the irradiation unit, onto an imaging surface, An imaging unit that captures an optical signal of the scattered light condensed by the imaging unit, converts it into an electrical signal, and performs imaging, A measuring unit that measures a moving distance or a speed of the elevator car based on the electrical signal converted by the imaging unit, Having, The irradiation unit has a light source that emits light, and an imaging element that can change an optical path of the light emitted from the light source. In the irradiation unit, the light emitted from the light source via the pixel element is incident on the guide rail in a direction substantially perpendicular to the moving direction of the elevator car. An elevator system characterized by this.

Images