Switching device

Abstract

Providing technology to appropriately control whether or not sensitivity learning of multi-axis sensors is possible. [Solution] In the opening / closing device 1, a pair of multi-axis sensors consisting of a light emitter 21 and a light receiver 23 are provided on both the left and right sides of the opening, slightly offset towards the indoor side from the closed opening / closing body 10. A liquid crystal panel 26 is installed in front of the lowest light receiving section 24b of the light receiver 23 so as to cover the entire section. Normally, the liquid crystal panel 26 is transparent when the liquid crystal is OFF, so light emitted from the light emitter 22b passes through the liquid crystal panel 26 and enters the light receiving section 24b. However, when the opening / closing body 10 is fully closed, it switches to the liquid crystal ON state, and the liquid crystal appears black, blocking the light, so the multi-axis sensors become sensing and sensitivity learning becomes impossible. As a result, sensitivity learning does not occur when the opening / closing body 10 is fully closed, which prevents the sensitivity from being over-adjusted due to inappropriate conditions where reflected light from the opening / closing body 10 is added.

Description

Technical Field

[0001] The present invention relates to an opening / closing device that opens or closes an opening of a structure including a building by the operation of an opening / closing body.

Background Art

[0002] In opening / closing devices, conventionally, in order to prevent an object or a person from being sandwiched when the opening / closing body descends, a photoelectric sensor is provided near the opening, and the operation of the opening / closing body is stopped or reversed according to the detection output by the photoelectric sensor. For example, Patent Document 1 discloses an electric shutter in which a multi-axis optical sensor composed of a plurality of light projecting / receiving portions is attached to the indoor side surface of guide rails provided on the left and right sides of an opening. In such an opening / closing device, when any one of a plurality of light beams formed by emitting light from each light projecting portion toward the corresponding light receiving portion is blocked, the multi-axis optical sensor outputs a detection output of an obstacle.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the opening / closing device as described above, in order to appropriately maintain the detection sensitivity of an obstacle according to the situation of the installation environment, there is a multi-axis optical sensor that periodically and automatically performs sensitivity learning to appropriately adjust its sensitivity (setting of a threshold value used for determination of detection). Sensitivity learning cannot be performed while any one of the light beams is blocked.

[0005] Here, referring to FIG. 6, the amount of incident light on the light receiver in the comparative example will be examined. As shown in Figure 6(A), when the open / close body 10' is not present near the multi-axis sensor paired with the light emitter 21' and light receiver 23' (when the open / close body 10' is located above the uppermost light-emitting / receiving section; for example, when fully open), the light ray B traveling in a straight line from the light emitter 21' enters the light receiver 23'.

[0006] In contrast, as shown in Figure 6(B), when the opening / closing body 10', guided down by the rails 41' with rollers 12' at both ends, is near the multi-axis sensor (when the opening / closing body 10' is positioned below the height of the uppermost light-emitting / receiving section; for example, when fully closed), in addition to the light ray B that travels straight from the light emitter 21', the light ray B reflected by the opening / closing body 10' also enters the light receiver 23'. As a result, the amount of light entering the light receiver 23' is greater than when the opening / closing body 10' is not near the multi-axis sensor. If sensitivity learning of the multi-axis sensor is performed with such an inappropriate amount of light entering, the sensitivity may be adjusted to be overly sensitive (the threshold may be set high). Subsequently, when the opening / closing body 10' rises and the reflected light disappears, reducing the amount of light entering the light receiver 23', there is a risk that a sensing output will be generated even though the light ray B is not blocked. In that case, the opening / closing body 10' will be unable to descend.

[0007] To avoid this situation, one method involves installing a light-shielding plate at the lower end of the opening / closing mechanism, which prevents sensitivity learning from occurring by ensuring that the plate constantly blocks the lowest light ray when the mechanism is fully closed. However, in this method, since the light-shielding plate blocks the light ray as the mechanism moves, during descent, blanking control is necessary, which assumes that the blocking is due to the light-shielding plate if the light rays are blocked sequentially from the top, and therefore does not generate a sensing output. Furthermore, during upward movement, the mechanism cannot be lowered again until it has been raised to a height where the light-shielding plate no longer blocks the highest light ray.

[0008] Thus, while providing a light-shielding plate allows for control to prevent sensitivity learning of the multi-axis sensor while the opening / closing mechanism is fully closed, it necessitates blanking control and partially restricts the operation of the opening / closing mechanism, thus requiring improvement.

[0009] Therefore, the present invention aims to provide a technology for appropriately controlling whether or not sensitivity learning of a multi-axis sensor is possible. [Means for solving the problem]

[0010] To solve the above problems, the present invention employs the following opening and closing device. Note that the following statements in parentheses are merely examples, and the present invention is not limited thereto.

[0011] In other words, the opening and closing device of the present invention comprises: an opening and closing means for opening or closing an opening; an obstacle sensing means provided at positions offset in the thickness direction from the opening and closing means in the closed position on both sides of the opening, with a light emitter on one side and a light receiver on the other side, which senses an obstacle based on a change in the amount of light entering the light receiver; a liquid crystal means provided in the optical path from the light emitter to the light receiver, which transmits light in the first state and blocks light in the second state by a change in liquid crystal; and a control means that controls the operation of the opening and closing means and the liquid crystal means, and switches the liquid crystal means from the first state to the second state at a predetermined timing.

[0012] According to this embodiment of the opening and closing device, when it is not desired to allow the obstacle detection means to perform sensitivity learning, the liquid crystal means can be switched from the first state to the second state, thereby transitioning to a state in which detection occurs by the obstacle detection means and sensitivity learning is impossible. This makes it possible to appropriately control whether or not sensitivity learning is possible. Furthermore, according to this embodiment of the opening and closing device, since no shielding plate is provided as described above, blanking control, which is essential when a light-shielding plate is provided, is unnecessary. Also, unlike when a light-shielding plate is provided, the opening can be re-closed while the opening and closing means is being opened. Therefore, it is possible to control whether or not sensitivity learning is possible without restricting the operation of the opening and closing means.

[0013] Preferably, in the opening / closing device according to the above-described embodiment, the control means switches the liquid crystal means from a first state to a second state when the opening / closing means reaches a lower limit position (for example, after a predetermined time has elapsed since reaching the lower limit position).

[0014] As described above, when the opening / closing mechanism is fully closed, not only light traveling straight from the light emitter but also light reflected by the opening / closing mechanism enters the light receiver. With this type of opening / closing device, by switching the liquid crystal means from the first state to the second state when the opening / closing mechanism reaches its lower limit position, the obstacle detection means can detect the obstacle and transition to a state where sensitivity learning is impossible. This prevents the sensitivity from being overly adjusted due to inappropriate light input while the opening / closing mechanism is fully closed.

[0015] More preferably, in the opening / closing device of any of the above embodiments, the obstacle sensing means is provided such that the optical axes of the multiple light-emitting units of the light emitter and the same number of light-receiving units of the light receiver coincide, a plurality of optical paths are formed from the light emitter to the light receiver, and the liquid crystal means is provided on at least one of the optical paths.

[0016] According to this embodiment of the switching device, by switching the liquid crystal means from a first state to a second state, one of the multiple light rays formed between the light emitter and the light receiver (between each light emitter and its corresponding light receiver) is blocked, thereby transitioning to a state in which sensitivity learning of the obstacle detection means is impossible.

[0017] More preferably, in the opening / closing device of any of the above embodiments, the liquid crystal means is installed outside the light-receiving part (for example, the lowest light-receiving part) or on the surface of the light-receiving lens included in the light-receiving part, so as to cover at least one of the light-receiving parts.

[0018] According to this embodiment of the opening and closing device, since the liquid crystal means is installed to cover one of the light-receiving parts, the light rays directed toward the light-receiving part can be blocked more reliably, and the device can be more reliably transitioned to a state in which sensitivity learning of the obstacle detection means is impossible. [Effects of the Invention]

[0019] As described above, according to the present invention, it is possible to appropriately control whether the sensitivity learning of the multi-optical axis sensor can be performed without restricting the operation of the opening / closing body.

Brief Description of the Drawings

[0020] [Figure 1] It is a perspective view showing an opening / closing device 1 of one embodiment. [Figure 2] It is a front view of the opening / closing body 10 seen from the indoor side. [Figure 3] It is a block diagram showing a configuration example of an electrical control system in the opening / closing device 1. [Figure 4] It is a view showing an enlarged light receiver 23 and its peripheral part. [Figure 5] It is a timing chart showing changes in various states accompanying the opening / closing of the opening / closing body 10. [Figure 6] It is a view for explaining problems regarding the sensitivity learning of the multi-optical axis sensor in the comparative example. <8000096>

Embodiments for Carrying Out the Invention

[0021] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiments are a preferred example of the opening / closing device, and the embodiments of the present invention are not limited to this example. Also, in order to ensure the visibility of the drawings, when there are a plurality of the same components, they may not all be labeled, and only some of them may be labeled.

[0022] 〔Configuration of the opening / closing device〕 FIG. 1 is a perspective view showing an opening / closing device 1 of one embodiment. The opening / closing device 1 is broadly comprised of an opening / closing body 10 that opens and closes an opening formed in the exterior wall of a building, multi-axis optical sensors 20 for detecting obstacles provided on both sides (left and right) in the width direction (left and right) of the opening, a drive unit 30 that drives the opening / closing body 10 and controls its operation, a guide unit 40 that guides the opening / closing body 10 driven by the drive unit 30 in a predetermined direction, and an operation unit 50 that receives user input regarding the operation of the opening / closing body 10. The opening / closing device 1 is a so-called overhead shutter that slides the opening / closing body 10 into the ceiling when open, and is installed in openings of structures including buildings, such as openings in the exterior walls of buildings such as office buildings, factories, and houses, or inside buildings.

[0023] The opening / closing body 10 consists of multiple horizontally elongated rectangular panels 11 that are rotatably connected to each other, with multiple rollers 12 (not shown in Figure 1) protruding from each of its left and right ends. The opening / closing body 10 opens and closes the opening by displacing itself between a lower limit position, which is a nearly vertical closed position, and an upper limit position, which is a nearly horizontal stored position, as these rollers 12 are guided by a guide unit 40 described later. In the following description, the movement of displacement in the direction of the upper limit position, i.e., the movement of opening the opening, will be referred to as the "opening operation," and the movement of displacement in the direction of the lower limit position, i.e., the movement of closing the opening, will be referred to as the "closing operation."

[0024] The multi-axis sensor 20 is positioned on both the left and right sides of the opening, slightly offset from the closed opening / closing body 10 towards the indoor side (in the thickness direction of the opening / closing body 10). It consists of a light emitter 21 located on one side of the opening and a light receiver 23 located on the other side, forming a pair. The configuration of the multi-axis sensor 20 will be described further later using another drawing.

[0025] The drive unit 30 includes, for example, an opening / closing controller 31 that houses a motor and a control panel, a power transmission rail 32 that transmits power supplied from the motor, a movable arm 33 with one end movably mounted on the power transmission rail 32 and the other end rotatably attached to the uppermost panel 11a of the opening / closing body 10, and a winding drum 34 that winds up a wire connected to the opening / closing body 10 by power transmitted via the movable arm 33.

[0026] In the power transmission rail 32, the drive-side pulley is positioned closer to the opening / closing controller 31, and the driven-side pulley is positioned closer to the opening. A roller belt is stretched between these pulleys, and this mechanism transmits power from the motor, enabling the reciprocating motion of the movable arm 33 on the power transmission rail 32.

[0027] The winding drum 34 is fixed to both ends of a shaft located inside the case 35 of the lintel section and rotates together with the shaft. Balance springs are provided around the shaft to bias it in the direction of winding the wire. One end of the wire is connected to the winding drum 34, and the other end is connected to the lowest panel 11b that forms the opening / closing body 10. In other words, the opening / closing body 10 is suspended by the wire.

[0028] The guide unit 40 has a guide rail that is integrally connected to vertical rail sections 41 that stand upright on both the left and right sides of the opening, a curved rail section 42 that curves diagonally upward from the upper end of the vertical rail section 41, and a horizontal rail section 43 that extends approximately parallel to the ceiling from the upper end of the curved rail section 42. Note that the vertical rail section 41 is located inside the guide case 44 and is therefore not shown in Figure 1.

[0029] When the movable arm 33 receives power and moves toward the opening / closing controller 31, the uppermost panel 11a is pulled, and the wire is wound onto the winding drum 34, causing the roller 12 to be guided toward the upper limit position by the guide rail, and the opening / closing body 10 opens. At this time, the biasing force of the balance spring assists the opening operation of the opening / closing body 10. On the other hand, when the movable arm 33 moves toward the opening, the uppermost panel 11a is pushed out, and the wire is unwound from the winding drum 34, causing the roller 12 to be guided toward the lower limit position by the guide rail, and the opening / closing body 10 closes. At this time, the action of the balance spring mitigates the impact and biasing force toward the closing direction due to the closing operation of the opening / closing body 10 and its weight.

[0030] The operating unit 50 consists of, for example, an operating section 51 mounted on a wall and a cord 52 for manual switching. The operating section 51 has three buttons corresponding to the open, stop, and close operations when the lid is in the open position. When the user presses any of the buttons, the opening / closing controller 31 controls the opening / closing body according to the user's operation. The cord 52 is provided as a countermeasure in case of a power outage, and pulling the cord releases the power transmission mechanism to the movable arm 33, allowing the opening / closing body 10 to be opened and closed manually. Alternatively, the user can be controlled by a wireless remote control with similar buttons, either in place of the operating section 51 or together with the operating section 51.

[0031] Figure 2 is a front view of the opening / closing body 10 as seen from the indoor side. To facilitate understanding of the invention, details are simplified in Figure 2, and the upper part is omitted from the illustration. Also, to ensure the visibility of the drawing, the number of light-emitting units 22 and light-receiving units 24 is shown fewer than the actual number.

[0032] As described above, the multi-optical axis sensors 20 are provided at positions slightly offset towards the indoor side from the closed opening / closing bodies 10 on both the left and right sides of the opening. On one side of the opening (the right side in the illustrated example), there is a light emitter 21 with multiple light-emitting units 22 arranged at approximately constant intervals, and on the other side (the left side in the illustrated example), there is a light receiver 23 with the same number of light-receiving units 24 as the light-emitting units 22 arranged at approximately constant intervals. The light emitter 21 and the light receiver 23 are installed so that their respective light-emitting units 22 and light-receiving units 24 face each other and their optical axes coincide.

[0033] The light receiver 23 has a built-in sensor control circuit 25. By emitting a predetermined light (for example, infrared light) from each light emitter 22, multiple light rays B (multiple optical paths from the light emitter 21 to the light receiver 23) are formed between the light emitter 21 and the light receiver 23 at approximately constant intervals in the height direction. If the light rays B are not obstructed, the expected amount of light enters each light receiver 24. However, if a light ray B is obstructed by some object, the amount of light entering the light receiver corresponding to the position of that light ray B decreases. The sensor control circuit 25 detects the change in the amount of light entering, determines the presence or absence of an obstacle based on this, and outputs an obstacle detection signal if it determines that an obstacle is present (obstacle detected).

[0034] Furthermore, a liquid crystal panel 26 is installed on the front side of the lowest light-receiving section 24b of the light receiver 23. The liquid crystal panel 26 is installed to control whether or not sensitivity learning of the multi-axis sensor 20 is enabled. The liquid crystal panel 26 has a structure in which liquid crystal is sandwiched between transparent electrodes. In the liquid crystal OFF state, when no voltage is applied to the electrodes, it is transparent and transmits light, but in the liquid crystal ON state, when voltage is applied, the molecular structure of the liquid crystal (more specifically, the refractive index, etc.) changes, and the liquid crystal appears black and blocks light. The liquid crystal panel 26 is normally maintained in the liquid crystal OFF state, but it can be switched to the liquid crystal ON state when sensitivity learning is not desired. The appearance of each ON / OFF state of the liquid crystal panel 26 and how to switch between them will be described in detail later with reference to another drawing.

[0035] [Control system configuration] Figure 3 is a block diagram showing an example of the configuration of the electrical control system in the switchgear 1. The switchgear controller 31 houses the control panel 36 and the motor 37. The control panel 36 is composed of a microcomputer and is electrically connected by wire or wireless means to the aforementioned operating unit 51, sensor control circuit 25, and liquid crystal panel 26. The control panel 36 is equipped with, for example, a drive control circuit 36a that controls the driving of the motor 37, and an input / output control circuit 36b that controls signal input from outside the switchgear controller 31 (operating unit 51, sensor control circuit 25) and signal output to the outside (liquid crystal panel 26).

[0036] The motor 37 is equipped with a limit switch 38 for detecting its rotational position. The limit switch 38 outputs a signal to the drive control circuit 36a indicating the position and state of the opening / closing body 10 according to the rotational position of the motor 37, and notifies the circuit when the opening / closing body 10 reaches the upper limit position or the lower limit position.

[0037] The operation unit 51 outputs an operation signal corresponding to the received operation (pressing any of the open button, stop button, or close button). The operation signal is sent to the drive control circuit 36a via the input / output control circuit 36b. The drive control circuit 36a controls the operation of the opening / closing body 10 by controlling the rotation of the motor 37 based on the operation signal and the signal from the limit switch 38, and stops the opening / closing body 10 when it reaches the upper limit position or the lower limit position.

[0038] The sensor control circuit 25 outputs an obstacle detection signal when it detects an obstacle. The obstacle detection signal is sent to the drive control circuit 36a via the input / output control circuit 36b. In response, the drive control circuit 36a prohibits the closing operation of the opening / closing body 10, and if the opening / closing body 10 is in the closing operation, it stops or reverses and raises the opening / closing body 10. Thus, since the closing operation of the opening / closing body 10 is prohibited in response to the obstacle detection signal, the obstacle detection signal can also be considered a closing operation prohibition signal.

[0039] Furthermore, when the opening / closing body 10 reaches its lower limit position, the drive control circuit 36a notifies the input / output control circuit 36b of this fact. The input / output control circuit 36b, a short delay after receiving this notification, that is, after a predetermined time has elapsed since the opening / closing body 10 reached its lower limit position, switches the liquid crystal panel 26 to the liquid crystal ON state.

[0040] The control system configuration described above is merely an example and is not limited thereto. For example, instead of the input / output control circuit 36b handling the exchange of signals inside and outside the control panel 36, the input / output control circuit 36b may be eliminated, and external signals may be directly input to the drive control circuit 36a, and external signals may be directly output from the drive control circuit 36a.

[0041] [Configuration of the multi-optical-axis sensor] Figure 4 is a magnified view of the light receiver 23 and its surrounding area. Figure 4(A) shows the photodetector 23 and its surrounding area when the opening / closing body 10 is not nearby (for example, when fully open) (viewed along the line IV-IV in Figure 2).

[0042] The light receiver 23 is located inside one of the guide cases 44. In this configuration, the vertical rail section 41 can be seen from a position slightly away from the light receiver 23 towards the outside. The light receiver 23 has multiple light-receiving sections 24 (for example, 32). Correspondingly, the guide case 44 has multiple (for example, 8) elongated holes 45 arranged vertically, with a certain number (for example, 4) of light-receiving sections 24 exposed from each elongated hole 45.

[0043] Although not shown in the diagram, the light emitter 21, like the light receiver 23, is located inside the other guide case 44, which has multiple elongated holes 45 formed therein. The width of the elongated holes 45 is designed to be such that it does not obstruct the spread of light emitted from the light emitter 22 at a predetermined angle.

[0044] The optical axis of the lowest light-receiving section 24b in the light receiver 23 is at a predetermined height H from the surface G that the opening / closing body 10 contacts when fully closed. b(For example, it is located at 150 mm), and the optical axis of the uppermost light-receiving section 24t is at a predetermined height H from the surface G. t It is located at (for example, 1500 mm). The same applies to the positions of the optical axes of the lowermost and uppermost light-emitting sections 22 of the floodlight 21. With this arrangement, the height H b More than H t In the following space, light rays (optical paths) corresponding to the number of light-emitting units 22 will be formed.

[0045] Furthermore, a liquid crystal panel 26 is installed in front of the bottommost light-receiving unit 24b, covering its entire surface. In this state, the liquid crystal panel 26 is in the OFF state and transparent, so the light emitted from the bottommost light-emitting unit 22b passes through the liquid crystal panel 26 and enters the bottommost light-receiving unit 24b.

[0046] Figure 4(B) shows the light receiver 23 and its surrounding area when the opening / closing body 10 is fully closed (a cross-sectional view along the line IV-IV in Figure 2). For the sake of clarity, details of the opening / closing body 10 (boundary lines and uneven shapes of each panel 11, connecting members, etc.) are omitted from this figure.

[0047] When the opening / closing body 10 reaches its lower limit position, the liquid crystal panel 26 switches to the liquid crystal ON state with a slight delay. As a result, the liquid crystal panel 26 appears black and blocks light, preventing light emitted from the lowest light-emitting unit 22b from entering the lowest light-receiving unit 24b. While the opening / closing body 10 is fully closed, the liquid crystal ON state is maintained, making it impossible for the multi-optical axis sensor 20 to learn its sensitivity.

[0048] Figure 5 is a timing chart showing the changes in various states related to the multi-optical-axis sensor 20 as the opening and closing of the opening / closing body 10 occurs. The following is an explanation in chronological order.

[0049] At time t0, the opening / closing mechanism 10 is in its upper limit position and fully open. At this time, the liquid crystal panel 26 is in the liquid crystal OFF state and is transparent. Also, the multi-axis sensor 20 is in a non-detecting state and is in a state where sensitivity learning is possible. Sensitivity learning is performed automatically at regular intervals when the multi-axis sensor 20 is in a non-detecting state.

[0050] At time t1, the closing mechanism 10 begins its closing operation upon the pressing of the closing button. At time t2, the presence of an obstacle causes the multi-axis sensor 20 to enter a detection state and output an obstacle detection signal. Consequently, the opening / closing body 10 stops, making sensitivity learning of the multi-axis sensor 20 impossible. If sensitivity learning was in progress, it is forcibly canceled. Time t3: The obstacle is removed. Consequently, the multi-axis sensor 20 returns to a non-detection state and also returns to a state where sensitivity learning is possible.

[0051] At time t4, the closing mechanism 10 resumes its closing operation upon the pressing of the closing button again. At time t5, the opening / closing mechanism 10 reaches its lower limit position and closes completely. At time t6, after a predetermined time (for example, 1 second) has elapsed since time t5, the liquid crystal panel 26 switches to the liquid crystal ON state and turns black. This blocks the light rays of the lowest row, causing the multi-axis sensor 20 to enter a sensing state, and also making it impossible to learn its sensitivity. The reason for switching the state of the liquid crystal panel 26 after a predetermined time has elapsed since time t5 is to allow for a margin of error in case of any problems, ensuring that the opening / closing body 10 is completely closed before the liquid crystal turns OFF.

[0052] Time t7: After a short while, the opening / closing mechanism 10 begins to open in response to the pressing of the release button. At time t8, after a predetermined time (for example, 10 seconds) has elapsed since time t7, during which the opening / closing body 10 has moved to a position where it can reliably move beyond the uppermost optical axis, the liquid crystal panel 26 switches to the liquid crystal OFF state and returns to transparent. As a result, the multi-optical axis sensor 20 returns to a non-detection state and also returns to a state where sensitivity learning is possible. By switching the liquid crystal panel 26 to the liquid crystal OFF state in this way, it is possible to avoid performing sensitivity learning while the opening / closing body 10 is close to the multi-optical axis sensor 20.

[0053] The timing for switching the liquid crystal panel 26 to the liquid crystal ON state is not limited to the above example; for example, it may be switched approximately in synchronization with the opening / closing body 10 reaching its lower limit position (at time t5). Similarly, the timing for switching the liquid crystal panel 26 to the liquid crystal OFF state is not limited to the above example; for example, it may be switched approximately in synchronization with the start of the opening operation of the opening / closing body 10 (at time t7), or slightly delayed from the start of the opening operation (for example, 1 second after time t7).

[0054] In this way, in this embodiment, the state of the liquid crystal panel 26 is switched after the opening / closing body 10 is fully closed to block the light rays of the lowest stage, thereby maintaining a state in which sensitivity learning of the multi-axis sensor 20 is impossible while the opening / closing body 10 is fully closed. Therefore, according to this embodiment, since sensitivity learning is not performed while the opening / closing body 10 is fully closed, it is possible to prevent the sensitivity from being over-adjusted as a result of sensitivity learning being performed when reflected light from the opening / closing body 10' enters the light receiver 23', as shown in the comparative example in Figure 6(B).

[0055] [Advantages of the present invention] As described above, the following effects can be obtained with the opening / closing device 1 of the embodiment. (1) A liquid crystal panel 26 is installed in a position that covers the lowest light-receiving section 24b. By switching this to the liquid crystal ON state, the light ray B is reliably blocked, making it difficult for light to enter the light-receiving section 24b, and the multi-optical axis sensor 20 enters a sensing state. This makes it possible to create a state in which sensitivity learning of the multi-optical axis sensor 20 is impossible at a desired timing.

[0056] (2) By switching the state of the liquid crystal panel 26 (liquid crystal ON / OFF), it is possible to switch whether or not to block light. Therefore, when you do not want to perform sensitivity learning on the multi-axis sensor 20, you can switch the liquid crystal panel 26 to the liquid crystal ON state, and when there are no problems with performing sensitivity learning, you can switch it to the liquid crystal OFF state, thereby appropriately controlling whether or not to perform sensitivity learning.

[0057] (3) After a predetermined time has elapsed since the opening / closing body 10 reached its lower limit position, the liquid crystal panel 26 is switched to the liquid crystal ON state, and this state is maintained while the opening / closing body 10 is fully closed, so that sensitivity learning does not occur. This prevents the sensitivity learning of the multi-optical axis sensor 20 from being performed in an inappropriate state when the amount of incoming light, including reflected light from the opening / closing body 10, is inappropriate while the opening / closing body 10 is fully closed, and thus prevents the sensitivity from being adjusted to be overly sensitive.

[0058] (4) Since the liquid crystal panel 26 is used to control whether or not sensitivity learning can be performed, there is no need to provide a light shield on the opening / closing body, and therefore blanking control, which is essential when a light shield is provided, is not required. In addition, the opening operation can be stopped again midway, and it is possible to control whether or not sensitivity learning of the multi-optical sensor 20 can be performed without restricting the operation of the opening / closing body 10.

[0059] The present invention can be implemented in various ways without being limited to the embodiments described above.

[0060] In the embodiment described above, the liquid crystal panel 26 is provided in a position that covers the lowest light-receiving section 24b. However, the liquid crystal panel 26 may be provided in a position that covers any other light-receiving section 24, or multiple or all of the light-receiving sections 24 may be provided with liquid crystal panels 26. Furthermore, instead of providing the liquid crystal panel 26 in a position that covers the light-receiving section 24, i.e., on the outside of the light-receiving section 24, the liquid crystal panel may be provided as part of the light-receiving section 24 on the surface of the light-receiving lens included in the light-receiving section 24. Moreover, instead of providing the liquid crystal panel on the light-emitting section 24, it is also possible to provide it on the light-emitting section 22. In other words, the liquid crystal panel 26 can be provided on any optical path from the light-emitting device 21 to the light-receiving device 23. However, in order to more reliably block the light entering the light-receiving section 24, it is desirable to provide it on the light-receiving section 24.

[0061] In the embodiment described above, the liquid crystal panel 26 is transparent and transmits light when the liquid crystal is OFF, and becomes black and blocks light when the liquid crystal is ON. However, the liquid crystal panel 26 only needs to be able to switch between transmitting and blocking light, and the color when the liquid crystal is ON is not limited to black.

[0062] In the embodiment described above, the state of the liquid crystal panel 26 is switched according to the operation of the opening / closing body 10. However, in addition to this, the state of the liquid crystal panel 26 may also be switched according to conditions unrelated to the operation of the opening / closing body 10, for example, by switching the liquid crystal panel 26 to the liquid crystal ON state only during specific time periods when there is a high probability that the conditions in the installation environment of the opening / closing device 1 will be far removed from normal conditions.

[0063] In the embodiment described above, the multi-optical-axis sensor 20 is provided on both the left and right sides of the opening, on the indoor side of the opening / closing body 10 in the closed position. However, in order to further enhance safety when the opening / closing body 10 is closing, the multi-optical-axis sensor 20 may be provided on both the indoor and outdoor sides.

[0064] In the embodiments described above, the ability to perform sensitivity learning on the multi-axis sensor 20 is controlled by switching the state of the liquid crystal panel 26. However, the target of sensitivity learning control is not limited to the multi-axis sensor 20. For example, it is also possible to install a liquid crystal panel on a single-axis or two-axis photoelectric sensor in any of the above-described manner and control whether or not to perform sensitivity learning on that sensor.

[0065] In the embodiments described above, an overhead type opening and closing device was used as an example. However, the application of the configuration for controlling the possibility of sensitivity learning of the multi-axis sensor is not limited to overhead type opening and closing devices, but can also be applied to other types of opening and closing devices. For example, the above configuration may be applied to so-called winding type opening and closing devices in which an opening and closing body made up of multiple connected slats is wound up and stored around a shaft, to opening and closing devices in which the opening and closing body is stored without being wound up around a shaft (for example, a panel shutter), or to opening and closing devices intended to close only a part of an opening rather than the entire opening (for example, a water-stopping panel that is suspended and moves up and down to close the lower side of an opening).

[0066] In the embodiment described above, an opening / closing device 1 in which an opening / closing body 10 opens and closes in the vertical direction over an opening equipped with multi-optical axis sensors 20 on both the left and right sides was explained as an example. However, it is also possible to apply the above-described configuration for controlling the ability to learn the sensitivity of the multi-optical axis sensors (photoelectric sensors) to an opening / closing device configured with the vertical and horizontal directions reversed, that is, an opening / closing device in which an opening / closing body opens and closes in the horizontal direction over an opening equipped with multi-optical axis sensors on both the vertical and horizontal sides.

[0067] Furthermore, the configurations and numerical values ​​mentioned in the explanation of the opening / closing device 1 are merely preferred examples, and it goes without saying that they can be modified as appropriate when implementing the present invention. [Explanation of Symbols]

[0068] 1. Switching device 10 Opening / closing mechanism (opening / closing means) 20. Multi-axis optical sensor (obstacle detection means) 21 Floodlight 22. Light-emitting section 23 Receiver 24 Light receiving part 26. Liquid crystal panel (liquid crystal means) 30 Drive Unit 36 Control panel (control means) 40 Guide Units 50 Operating Units

Claims

1. An opening / closing mechanism for opening or closing an opening, An obstacle detection means is provided at a position offset in the thickness direction from the opening and closing means in the closed position on both sides of the opening, and consists of a light emitter on one side and a light receiver on the other side, which detects an obstacle based on a change in the amount of light entering the light receiver, A liquid crystal means is provided in the optical path from the light emitter to the light receiver, which transmits light in the first state and blocks light in the second state by changing the liquid crystal, Control means for controlling the operation of the opening / closing means and the liquid crystal means, and for switching the liquid crystal means from a first state to a second state at a predetermined timing. A switching device equipped with the following features.

2. In the opening and closing device according to claim 1, The control means is An opening / closing device characterized in that the liquid crystal means is switched from the first state to the second state when the opening / closing means reaches the lower limit position.

3. In the opening and closing device according to claim 2, The control means is An opening / closing device characterized in that, after a predetermined time has elapsed since the opening / closing means reached its lower limit position, the liquid crystal means is switched from the first state to the second state.

4. In the opening and closing device according to claim 1 or 2, The obstacle detection means is The optical axes of the multiple light-emitting units of the light emitter and the same number of light-receiving units of the light receiver are arranged to coincide, and multiple optical paths are formed from the light emitter to the light receiver. The liquid crystal means is A switching device characterized by being provided on at least one of the aforementioned optical paths.

5. In the opening and closing device according to claim 4, The liquid crystal means is An opening / closing device characterized by being installed on the outside of at least one of the light-receiving parts, or on the surface of a light-receiving lens included in the light-receiving part, so as to cover the light-receiving part.

6. In the opening and closing device according to claim 5, The liquid crystal means is An opening / closing device characterized by being installed so as to cover the light-receiving section at the lowest level.

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