JP2005050053A - Optical curtain - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To appropriately arrange a light emitting element and a light receiving element. <P>SOLUTION: This optical curtain is constructed of two thin long blocks to form a monitoring area defined between the blocks. The optical curtain has a surface striped by alternately formed thin color areas 13 and dense color areas 12 so that the respective blocks P1 and P2 form a grid to each other. A linear/matrix type light receiving apparatus having a proper optical component photographs an image of the grid, and processing means of the both blocks process the respective image signals to give invasion signals. Desirably, the respective blocks have two linear light receiving apparatus RH1 and RB1 and two linear light receiving apparatus RH2 and RB2 adjacent to both ends, and the optical components cooperating with the respective light receiving apparatus cover the overall length of the opposite blocks, while the processing means perform redundant processing of the image inside the monitoring area. <P>COPYRIGHT: (C)2005,JPO&amp;NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention comprises two elongated blocks that form a longitudinally defined monitoring zone between the blocks and provide at least one light source, at least one light receiver, and a light receiving device to provide an intrusion signal. The present invention relates to a light curtain having processing means capable of processing a signal received from a light source.
[0002]
[Prior art]
A conventional light curtain consists of two elongated blocks, one having a series of light emitting elements and the other having a series of light receiving elements. As performance increases and price decreases, when using CCD or CMOS linear or matrix sensors as light receiving elements, these elements and corresponding processing means are appropriately arranged to form a light curtain. Is required.
[0003]
[Problems to be solved by the invention]
An object of the present invention is to provide the required safety light curtain.
[0004]
[Means for Solving the Problems]
According to the present invention, each block has a surface in which light areas and dark areas are alternately provided in the longitudinal direction of the block so as to form a grid with respect to the other blocks, and each block has a block. At least one linear (or matrix type) photoreceiver having photosensitivity points arranged sequentially in the vertical direction, and an optical component capable of taking at least a part of the image in the vertical direction of the opposing grating in cooperation with the linear photoreceiver The linear light receiver takes an image of a part of the opposing grating, transmits a corresponding lattice image signal, and the lattice image signals from the respective linear light receivers are processed by the processing means of both blocks. Provide an intrusion signal.
[0005]
Each block may have only one linear receiver close to the end, with its associated optical components covering the entire length of the opposing block, with the receiver in each block located at the opposite end . Preferably, for increased safety, each block has two linear receivers close to both ends, the optical components associated with each receiver of the block cover the entire length of the opposing block, and the processing means is a monitoring area It has extra safety processing means.
[0006]
Preferably, the processing means of one block can supervise the processing means of the other block, in which case the processing means of both blocks send a diagnostic signal from the supervised block to the master block and They are connected by an electric wire or an optical connection that transmits a synchronization signal between the light source of the block and the light receiver of the other block.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
By way of example, the features and advantages will become apparent in the detailed description with reference to the embodiments illustrated in the accompanying drawings.
[0008]
The light curtain shown in the drawing is composed of two blocks P1 and P2 arranged to face each other with the monitoring area 10 in between. Each of the blocks P1 and P2 has a case, and each case has a surface provided with a dark streak or stripe 12 separated by a slit 13 that can be illuminated or pass a light-emitting beam, and the other case. Opposite to. In order to detect an intruder such as a finger, the width and the interval between the streak and the slit which are alternated are set to, for example, 3 mm.
[0009]
Each block further has two light receivers R, denoted as RH1 and RB1 in P1, and as RH2 and RB2 in P2. The sensor R is a CCD, CMOS or analog linear or matrix sensor. In this specification, to be precise, both linear and matrix types are referred to as linear to simplify the terminology.
[0010]
The sensors RH1 and RH2 approach the end of the corresponding block (upper end in the drawing), while the sensors RB1 and RB2 approach the other end of the block (lower end in the drawing). Each sensor is associated with a lens or an optical component that can receive a beam having a predetermined angle corresponding to the total height of the opposing stripe pattern. This angle is not limited, but illustratively it is about 15 to 60 degrees.
[0011]
The device can be operated with only one receiver R per block, for example, if P1 has RH1 and P2 has RB2, each receiver monitors the triangle zone 15 or 16, Together, the two zones cover the entire area 10. Further, three or more light receivers can be provided in one block, and for example, the light receivers can be positioned at both ends and the center of the block.
[0012]
However, as described above, it is desirable that each block has two light receivers so as to cover the area 10 redundantly, and as a result, the safety process can be performed by monitoring the crossing of the triangular zones 15, 16 and 17, 18. It can be done easily and makes it possible to determine the position and size of the intruder.
[0013]
Each block has intermittent light sources E1 and E2 that are synchronized with the operation of the light receivers of the opposing blocks.
[0014]
The processing means includes circuits 21 and 22 using software means, and controls the periodic light emission of the light sources 17 and 18 of the blocks P1 and P2, the synchronous action of the sensors R of the opposing blocks P1 and P2, And in order to perform processing of the image signal, it cooperates with the blocks P1 and P2, respectively. For this purpose, the circuit 21 has two controllers 23 and 24 linked to RH1 and RB1, respectively, and the circuit 22 has two controllers 25 and 26 linked to RH2 and RB2, respectively. Block P 2 is supervised by block P 1, the “master” block, controller 23 oversees controller 26 and controller 24 oversees controller 25. It has a relay that generates an output signal S representing the default state or entry into the zone 10 in response to processing.
[0015]
The optical connecting portion located outside the erasing area (blanking area) indicated by 28 in FIG. 3 transmits the diagnostic signal D of the image in the monitoring area, in particular, from the light emitting element of the block P2 to the light receiving element of the block P1, and the diagnostic signal D consists of signals from the controllers 25 and 26 connected by the logical OR means 29. Alternatively, as shown by a dotted line 30, an electric wire can be used as a connection. In this way, the connection unit 28 or 30 also transmits a synchronization signal SYNC that synchronizes the start signal STR of each controller cycle and the corresponding light emission signal SE.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a light curtain according to the present invention.
FIG. 2 shows a perspective view of a light curtain.
FIG. 3 shows details of the curtain of FIGS.
[Explanation of symbols]
10 Monitoring area 11 Surface 12 Streak (stripe)
13 Slit 15-18 Triangular Zone 21-22 Circuit 23-26 Controller 28 Connection 29 Logical OR Means 30 Connection

Claims (7)

At least one light source, at least one light receiver, and a light receiver from the light source to form a monitoring zone defined in the longitudinal direction between the blocks and to provide an intrusion signal A light curtain having processing means for processing a received signal,
Each block (P1, P2)
A surface (11) provided with alternating light-colored areas (13) and dark-colored areas (12) in the longitudinal direction of the blocks so as to form a grid, and-light sensitive spots arranged sequentially in the longitudinal direction of the blocks And at least one linear (or matrix) receiver (R) and an optical component (14) associated with the linear receiver that can take at least a portion of the image in the longitudinal direction of the opposing grating;
-The linear light receiver (R) takes an image of a part of the opposing grating and transmits the corresponding grating image signal; and-the processing means (23-26) of both blocks (P1, P2) respectively A light curtain, characterized by processing a grid image signal from a linear light receiver to provide an intrusion signal. Each block (P1, P2) has only one linear light receiver (23, 26) close to the end, whose associated optical component (14) covers the entire length of the opposing block (P2, P1). 2. The light curtain according to claim 1, wherein the light receivers (RB2, RH1) of the respective blocks are located at opposite ends. 2. Detection according to claim 1, characterized in that the detection is periodic and each block has intermittent internal light sources (E1, E2) synchronized with the action of the linear light receivers (R) of the opposing blocks. Light curtain. Each block (P1, P2) has two linear light receivers (RH1, RB1 and RH2, RB2) close to both ends, and an optical component (14) linked to each light receiver of the block is a counter block (P2, P2). 2. The light curtain according to claim 1, characterized in that it covers the entire length of P1) and that the processing means (21, 22) have extra safety processing means in the monitoring area. The processing means (21, 23, 24) of one block (P1) supervises the processing means (22, 25, 26) of the other block, and the processing means of both blocks receive diagnostic signals (D ) Is transmitted to the master block, and the synchronization signal (SYNC) between the light source (E) of one block and the light receiver (R) of the other block is connected by the connecting portions (28, 30). The light curtain according to claim 4. 6. A light curtain according to claim 5, characterized in that the connecting part (28) is an optical connecting part. The light curtain according to claim 5, wherein the connecting portion is a wire connecting portion.

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