JP2005300525A - Sensor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a displacement sensor device capable of performing data reading or processing at high speed. <P>SOLUTION: The displacement sensor device comprises a light emitting element for irradiating a measuring object with light at a predetermined angle; an imaging element for imaging the measuring object irradiated with light from another angle; a general measuring area setting means capable of setting a general measuring area within the visual field of the imaging element; a light receiving signal detection means detecting a light receiving signal distribution area of the measuring object from the set general measuring area; a follow-up measuring area setting means setting at least one follow-up measuring area including the detected light receiving signal distribution area and narrower than the general measuring area; a displacement measuring means performing an intended displacement measurement by measuring the follow-up measuring area; and an output means outputting a displacement measured by the displacement measuring means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sensor device that can reduce measurement processing time.

Conventionally, sensor devices for measuring the displacement, length, angle, and the like of various measurement target objects are known. For example, in a conventional displacement sensor device, a light projecting element such as a laser diode is driven to irradiate a measurement target object with slit light, and a light emitted from the light projecting part is reflected on the measurement target object. A light receiving unit that receives the incoming slit light, a calculation unit that calculates the distance to the measurement target object, and an output unit that outputs the distance to the measurement target object calculated by the calculation unit. (For example, refer to Patent Document 1).
International Publication No. 01/57471 Pamphlet

  As shown in FIG. 15, the measurement target objects [1], [2], and [3] are conveyed on the line (moved from the right to the left in the figure), and the sensor head unit 1501 of the displacement sensor device is the measurement target object. Assume that the measurement target object is irradiated with slit light from a direction perpendicular to the conveyance direction (vertical direction in the figure) and reflected light from the measurement target object is received. If the measurement target object “1” shown in FIG. 15 is a standard arrangement on the line, the measurement target object “2” is arranged on the side close to the sensor head unit 1501, and the measurement target object “3” is the sensor head unit 1501. It is arranged on the far side. As described above, the arrangement of the measurement target object on the line may vary.

  In the rectangular field of view Z (light receiving surface) of the two-dimensional image sensor built in the sensor head unit 1501, as shown in FIG. 16, the irradiated light images [1], [2], [3 corresponding to the measurement target object are shown. ] Are arranged. In the drawing, the left side is the direction close to the sensor head unit 1501, and the right side is the direction far from the sensor head unit 1501. Moreover, while setting a horizontal line (displacement measurement direction) along the longitudinal direction of the rectangular field of view Z, a vertical line (extending direction of the irradiation light image) is assigned to a direction orthogonal thereto. In this case, a rectangular measurement area surrounded by a broken line is set as a normal measurement area so that the irradiation light images [1], [2], and [3] can be measured.

  When the variation range A shown in FIG. 15 is wide, the measurement region widens, or the measurement region shown in FIG. Thus, there is an inconvenience that the longer the measurement area, the longer the time required for data reading.

  The present invention has been made paying attention to such conventional problems, and an object of the present invention is to provide a sensor device capable of high-speed data reading and arithmetic processing.

  Other objects and operational effects of the present invention will be easily understood by those skilled in the art by referring to the following description of the specification.

  A sensor device according to the present invention includes a light projecting element for irradiating a measurement target object with light at a predetermined angle, an image sensor for photographing the measurement target object irradiated with light from another angle, and an image sensor. Normal measurement area setting means capable of setting a normal measurement area within the visual field of the image sensor, and irradiation light for detecting the position of the irradiated light image within the visual field of the image sensor by scanning the set normal measurement area An image position detection unit, a tracking type measurement region setting unit that sets at least one tracking type measurement region that includes the position of the detected irradiation light image and is narrower than the normal measurement region in the displacement measurement direction, and a tracking type Displacement measuring means for measuring the target displacement by measuring the measurement region, and output means for outputting the measured displacement are provided.

  The “displacement measurement direction” here refers to a direction in which the position of the irradiated light image detected by the displacement of the measurement target object changes.

  According to such a configuration, the normal measurement region is used to detect the irradiation light image corresponding to the measurement target object, and the target displacement is not measured here. On the other hand, a follow-up measurement region that includes the position of the irradiation light image and is narrower in the displacement measurement direction than the normal measurement region is used to measure the target displacement. Therefore, since the measurement area where data is read can be set narrower than before, data can be read and calculated at high speed.

  In the embodiment of the present invention, the irradiation light image position detecting means performs the thinning measurement over the data arranged at a predetermined interval in the displacement measuring direction of the image sensor, thereby obtaining the density value distribution of the received light signal in the field of view of the image sensor. Measurement may be performed in the displacement measurement direction, and the position of the irradiation light image may be detected based on the measured density value distribution.

  According to such a configuration, it is possible to reduce the number of measurement points that are targets for detecting the position of the irradiation light image, so that higher-speed processing is possible.

  In the embodiment of the present invention, in the irradiation light image position detection means, the light projecting element emits slit light, the imaging element is a two-dimensional imaging element, and at least one of the displacement measurement directions in the field of view of the two-dimensional imaging element. It is also possible to measure the density value distribution of the received light signal for the line in the displacement measurement direction and detect the position of the irradiated light image based on the measured density value distribution.

  According to such a configuration, the density value distribution of the received light signal is measured for one line or more in the displacement measurement direction, and thus the received light signal distribution area is detected from the normal measurement area based on the density value distribution. Thereby, the position of the irradiation light image can be accurately detected.

  In the embodiment of the present invention, the concentration value distribution is measured by performing all line measurement over all data in the displacement measurement direction in the measurement region, or by performing thinning measurement over data arranged at predetermined intervals in the displacement measurement direction. You may be made to do. According to such a configuration, the position of the irradiation light image can be obtained with high accuracy according to all line measurement, so that error detection can be prevented in advance. In addition, when thinning measurement is performed, data reading and processing can be performed at high speed.

  In the embodiment of the present invention, the irradiation light image position detecting means detects the received light signal with respect to the displacement measurement direction in an area other than the normal measurement area in the field of view of the image sensor when the irradiation light image is not detected in the normal measurement area. The density value distribution can be measured for all lines or thinned.

  In the embodiment of the present invention, the light projecting element irradiates slit light, the image sensor is a two-dimensional image sensor, and the irradiation light image position detection unit is configured to detect the irradiation light image in the normal measurement region. In the area other than the normal measurement area in the field of view of the two-dimensional image sensor, the concentration value distribution of the received light signal may be measured for all lines or thinned out for at least one line in the displacement measurement direction. .

  According to such a configuration, even if the position of the irradiation light image cannot be detected at one time, the area other than the normal measurement region is measured, so that it is possible to prevent error detection due to the fact that the position of the irradiation light image cannot be detected. .

  In the embodiment of the present invention, the measurement target object is a transparent body, two follow-up measurement areas are provided corresponding to the front and back surfaces of the transparent body, and the two follow-up measurement areas are switched and measured. May be. According to such a configuration, the front and back surfaces of the transparent body can be measured with high accuracy.

  In the embodiment of the present invention, the thickness of the transparent body is measured by performing thinning measurement over data arranged at a predetermined interval in the displacement measurement direction connecting the irradiation light images arranged in the two tracking measurement regions. Also good. According to such a configuration, the thickness of the transparent body can be measured at high speed.

  In the embodiment of the present invention, the imaging device may be configured by any one of a photodiode array, a CCD, and a CMOS imaging device. The “imaging device” mentioned here includes a one-dimensional imaging device and a two-dimensional imaging device.

  In the embodiment of the present invention, the image sensor is constituted by a CMOS image sensor, and the irradiation light image position detecting means reads out pixel data of the normal measurement area and the follow-up measurement area set directly from the CMOS image sensor. In this case, since the number of pixels to be read from the CMOS image sensor can be reduced, higher speed processing is possible.

  In the embodiment of the present invention, it may be configured as a displacement sensor, a length measurement sensor, or an angle sensor.

  As is apparent from the above description, according to the present invention, the measurement area where data is read is set narrower than before by narrowing the measurement area of the irradiation light image from the normal measurement area to the follow-up measurement area. As a result, data can be read and processed at high speed. Therefore, for example, there is an advantage that measurement can be performed following a measurement object conveyed while meandering on the line.

  Hereinafter, a preferred embodiment of a sensor device of the present invention will be described in detail with reference to the accompanying drawings. The embodiment described below is merely an example of the present invention, and the gist of the present invention is defined only by the description of the scope of claims.

  The displacement sensor according to the present embodiment has a signal processing unit and a sensor head unit separated from each other in order to enable compact accommodation in a control panel or the like and to facilitate installation in a narrow measurement environment. This is a so-called amplifier separation type displacement sensor.

  An external perspective view of a signal processing unit of the displacement sensor of the present embodiment is shown in FIG. The outer shell case 10 of the signal processing unit 1 has a slightly elongated rectangular parallelepiped shape. An external connection cord 11 is drawn out from the front surface of the outer shell case 10. The external connection cord 11 includes an external input line, an external output line, a power supply line, and the like. The external input line is used to give various commands to the signal processing unit 1 from, for example, a PLC as a host device, and the external output line is a switching output or analog generated inside the signal processing unit 1 The power supply line is used to supply power to the internal circuit of the signal processing unit. In addition, a USB connector 12 and an RS-232C connector 13 are provided on the front surface of the outer shell case 10.

  An operation unit lid 14 that can be opened and closed is provided on the upper surface of the outer shell case 10. Although not shown, an operation unit for performing various command operations in the signal processing unit 1 is provided below the operation unit lid 14. Further, on the upper surface of the outer shell case 10, a display unit 15 for performing operation display and the like is disposed.

  On the left and right sides of the outer shell case 10, signal processing unit connector covers 16 are provided. Inside the signal processing unit connector lid 16, a signal processing unit connector (relay connector 3) for connecting another signal processing unit 1 is provided.

  FIG. 2 is an external perspective view showing a state in which a plurality of signal processing units 1 are connected. As shown in the figure, a plurality of signal processing units 1 are connected in a row in an adjacently coupled state via a DIN rail 4 in this example. A sensor head connector 17 is provided on the rear surface of the outer case 10 of the signal processing unit 1. The signal processing unit 1 is connected to the sensor head unit 2 described later via the sensor head unit connection connector 17.

  An external perspective view of the sensor head portion is shown in FIG. The sensor head unit 2 includes a signal processing unit connection connector 27 corresponding to the sensor head unit connection connector 17, a cable 21, and a sensor head body unit 20. Then, pulsed laser light (pulse light) emitted from a light projecting element (laser diode) incorporated in the main body 20 is irradiated as slit light L1 on the surface of the measurement target object 5 through a light projecting lens (not shown). The Thereby, an irradiation light image LM of slit light is formed on the surface of the measurement target object 5. The reflected light L2 of the slit light reflected by the measurement target object 5 is incident on a two-dimensional image sensor (photodiode array, CCD, CMOS image sensor, etc.) through a light receiving lens (not shown) in the sensor head unit 2. That is, a video signal including the irradiation light image LM of the slit light is acquired by photographing the surface of the measurement target object 5 from different angles with the two-dimensional image sensor. Based on this video signal, a predetermined feature amount is extracted, and a target displacement amount (in this example, a distance between the sensor head unit 2 and the measurement target object 5) is obtained.

  In the present embodiment, the light projecting element irradiates slit light and uses the two-dimensional image sensor to acquire the irradiated light image formed on the surface of the measurement target object. It is also possible to perform displacement measurement by simply irradiating condensed light from the element, obtaining an irradiation light image formed on the measurement target object by a one-dimensional image sensor.

  FIG. 4 is a block diagram showing the entire electrical hardware configuration of the signal processing unit 1 of the displacement sensor. As shown in the figure, the signal processing unit 1 includes a control unit 101, a storage unit 102, a display unit 103, a communication unit 104 with a sensor head unit, a communication unit 105 with an external device, and key input. Unit 106, external input unit 107, output unit 108, and power supply unit 109.

  The control unit 101 constitutes a normal measurement area setting means, an irradiation light image position detection means, a follow-up measurement area setting means, and a displacement measurement means, and includes a CPU (Central Processing Unit) and an FPGA (Field Programmable Gate Array). And is responsible for overall control of the signal processing unit 1 as a whole. The control unit 101 realizes various functions to be described later, binarizes the received light signal with a predetermined threshold as a reference, and sends this as output data from the output unit 108 to the outside.

  The storage unit 102 includes a nonvolatile memory (EEPROM) 102 a and an image memory 102 b that stores image data displayed on the display unit 103.

  The display unit 103 includes a liquid crystal display unit 103a on which various numerical values relating to a threshold value, a distance to an object to be measured, and the like, and a display lamp LED 103b that indicates an on / off state that is a target output. ing.

  The communication unit 104 is responsible for communication with the sensor head unit 2.

  The external communication unit 105 includes a USB communication unit 105a for connecting to an external personal computer (PC) 110, a serial communication unit 105b used for transmission / reception of commands and program data, and the right and left according to a predetermined protocol and transmission / reception format. And an inter-signal processing unit communication unit 105c that performs data communication with other adjacent signal processing units.

  The key input unit 106 includes switches and operation buttons for various settings (not shown). The external input unit 107 is for receiving various commands to the signal processing unit 1 from a host device such as a PLC. The output unit 108 is used to output a desired on / off output to a host device such as a PLC. The power supply unit 109 supplies power to the control unit 101 and an external hardware circuit.

  A block diagram showing the electrical hardware configuration of the sensor head unit 2 is shown in FIG. As shown in the figure, the sensor head unit 2 is reflected by the control unit 201, the light projecting unit 202 for irradiating slit light toward the measurement target object 5, and the measurement target object 5. A light receiving unit 203 that receives slit light, an indicator LED 204, a storage unit 205, and a communication unit 206 are provided.

  The control unit 201 includes a CPU (Central Processing Unit) and a PLD (Programmable Logic Device). The control unit 201 performs overall control of each of the components 202 to 206 of the sensor head unit, extracts a received light signal from the light receiving unit 203, and performs signal processing. It is responsible for processing to be sent to the part 1.

  In this example, the light projecting unit 202 includes a laser diode as a light projecting element and a light projecting circuit, and irradiates slit light toward the measurement target region. The light receiving unit 203 is obtained from the two-dimensional image sensor in synchronization with a two-dimensional image sensor (photodiode array, CCD, CMOS image sensor, etc.) that receives the reflected light of the slit light and a timing control signal from the control unit 201. A received light signal processing unit that amplifies the received light signal and outputs the amplified received light signal to the control unit 201. The indicator LED 204 is turned on and off in response to various operating states of the sensor head unit 2.

  The storage unit 205 is configured by, for example, a nonvolatile memory (EEPROM), and in this example, an ID (identification information) for identifying the sensor head unit 2 is recorded. The communication unit 206 is responsible for communication with the signal processing unit 1 in accordance with instructions from the control unit 201.

  The sensor head unit 2 of the present embodiment has a circuit configuration as described above, and performs an appropriate light projecting / receiving process according to a command from the signal processing unit 1.

  A general flowchart showing the operation of the signal processing unit 1 of the displacement sensor in the present embodiment is shown in FIG. When processing is started by turning on the power, initial setting processing such as initial processing (step 601) is performed, and then the setting mode is read. Specifically, it is determined which of the FUN mode, TEACH mode, and RUN mode is switched (step 602).

  When the setting mode is “FUN mode”, the FUN mode initial setting process (step 603) is performed, and then the FUN mode process described later is performed (step 604). Subsequent to step 604, it is determined whether or not the FUN mode is continued (step 605). In other words, when switching to another setting mode is performed, the process returns to step 602, and when there is no switching, the process returns to step 604.

  When the setting mode is “TEACH mode”, the TEACH mode initial setting process (step 606) is performed, and so-called teaching process is performed, and various setting values are automatically read (step 607). Following step 607, it is determined whether the TEACH mode is continued (step 608). In other words, when switching to another setting mode is performed, the process returns to step 602, and when there is no switching, the process returns to step 607.

  When the setting mode is “RUN mode”, the RUN mode initial setting process (step 609) is performed, and then the RUN mode process described later is performed (step 610). Subsequent to step 610, it is determined whether or not the RUN mode is continued (step 611). In other words, when switching to another setting mode is performed, the process returns to step 602, and when there is no switching, the process returns to step 610.

  Details of the FUN mode processing (step 604) are shown in the flowchart of FIG. In the FUN (Function) mode process, display according to function is made on the display unit 15 (step 701). At the same time, the presence / absence of key input (operation of the operation unit below the operation unit lid 14) is always detected (step 702). When a predetermined key input is detected (YES in step 703), it instructs function switching. It is confirmed whether to execute the function (YES in step 704) or to instruct execution of the function (YES in step 706). If it is a function switching instruction (step 704 YES), function switching is performed (step 705). On the other hand, if it is an instruction to execute a function (YES in step 706), a function execution process is performed.

  Details of the RUN mode process (step 610) are shown in the flowchart of FIG. In the RUN mode processing, display control processing (step 801) of the display unit 15, sensor head control processing (step 802), and communication command execution processing from an external device are sequentially executed. Then, the presence / absence of key input (operation of the operation unit under the operation unit lid 14) is confirmed (step 804). When a predetermined key input is detected (YES in step 805), key input processing corresponding to that is executed. (Step 806). Next, the presence / absence of an external input via the communication unit 105 is confirmed (step 807). If there is a predetermined external input (YES in step 807), an external input process corresponding to that is executed. Next, the presence / absence of external communication via the communication unit 105 is confirmed (step 809), and if there is predetermined external communication (YES in step 809), external communication processing corresponding to that is executed (step 810).

  The displacement sensor device of this embodiment is provided with an automatic follow-up measurement mode as an example of the RUN mode sensor head control process (step 802). In the displacement sensor of this embodiment, a plurality of measurement target objects are conveyed on the line, and the sensor head unit 2 of the displacement sensor irradiates the measurement target object with slit light from a direction perpendicular to the conveyance direction of the measurement target object. It is assumed that it is used to receive reflected light from an object to be measured. Hereinafter, the automatic tracking measurement mode will be described in detail.

  A general flowchart showing the process in the automatic tracking measurement mode is shown in FIG. When the process is started, the mode setting is read to determine whether the operation mode is the high-speed area automatic tracking measurement mode or the multi-area automatic tracking measurement mode (step 901).

  When the operation mode is the high-speed area automatic follow-up measurement mode, a high-speed area automatic follow-up measurement process described later is performed (step 902). Subsequent to step 902, it is determined whether or not the high-speed area automatic follow-up measurement mode is continued (step 903). In other words, when switching to another setting mode is performed, the process returns to step 901, and when there is no switching, the process returns to step 902.

  When the operation mode is the multiple area automatic tracking measurement mode, a multiple area automatic tracking measurement process described later is performed (step 904). Subsequent to step 904, it is determined whether or not the multi-region automatic follow-up measurement mode is continued (step 905). In other words, when switching to another setting mode is performed, the process returns to step 901, and when there is no switching, the process returns to step 904.

  The high-speed area automatic tracking measurement process will be described with reference to the flowchart shown in FIG. 10 and the explanatory diagrams shown in FIGS. When the process shown in FIG. 10 is started, a process for setting a measurement area (normal measurement area) for tracking is executed (step 1001).

  Here, Z shown in FIG. 12 represents a rectangular field of view (light receiving surface) of the two-dimensional image sensor provided in the light receiving unit 203. In the drawing, the left side is a direction close to the sensor head unit 2, and the right side is a direction far from the sensor head unit 2. A horizontal line X (displacement measurement direction: number of data Xn) is set along the longitudinal direction of the rectangular field of view Z, while a vertical line Y (extension direction of the irradiated light image: number of data Yn) is orthogonal to the horizontal line X. Has been assigned. In step 1001, a rectangular measurement area surrounded by a chain line with the coordinate position (X1, Y1) and the coordinate position (X2, Y2) as opposite end points is set as a normal measurement area. Note that the normal measurement region is stored in advance in the storage unit 205 of the sensor head unit 2.

  Subsequent to step 1001, a process for acquiring light receiving position data is executed (step 1002). Here, with respect to the normal measurement region set in step 1001, the data between the horizontal lines X is thinned out and a predetermined density value distribution (luminance distribution) is acquired. At this time, for example, the data of one line at the center of the horizontal line in the normal measurement region is measured while being thinned out in the displacement measurement direction.

  Subsequently, it is determined whether or not a light reception data area exists (step 1003). When there is a light reception data area (when there is an irradiation light image in the normal measurement area), a tracking area measurement process (step 1004) for setting the tracking measurement area and measuring the target displacement is executed. As an example of the case where a light reception data area exists, the density value distribution (luminance distribution) when one line of the horizontal line X is thinned in the displacement measurement direction at the thinning interval α for the normal measurement area set in step 1001. It is shown in FIG. Since the area where the light reception signal of the irradiation light image is distributed is obtained from this density value distribution, X3 to X4 are set as distribution areas in the horizontal line direction so as to include this light reception signal distribution area. Then, as the follow-up type measurement area, as shown in FIG. 12, a rectangular measurement area surrounded by a broken line with the coordinate position (X3, Y3) and the coordinate position (X4, Y4) as opposite end points is set. Then, measurement processing is executed in detail over all the lines in the follow-up measurement region, and target measurement results (for example, displacement, sensitivity, peak value, etc.) are output (step 1005). Following step 1005, the process returns to step 1002 again.

  On the other hand, in step 1003, when there is no light reception data area (when there is no irradiation light image in the normal measurement area), a light reception position confirmation process is executed (step 1006). At this time, a measurement area other than the normal measurement area set in step 1001 is set within the field of view of the two-dimensional image sensor. Then, a process for acquiring the light reception position data is executed, and it is determined again whether or not there is a light reception data area (step 1007). If there is a light reception data area, the process returns to step 1004. If there is no light reception data area, a measurement error output is executed (step 1008), and the process returns to step 1002.

  As described above, the sensor head unit shown in FIG. 3 and the signal processing unit shown in FIG. 1 cooperate with each other according to the displacement sensor of this embodiment. The tracking type measurement area narrower than the normal measurement area is set. Then, the target displacement is measured by measuring the follow-up measurement region based on the image photographed by the two-dimensional image sensor.

  When a one-dimensional image sensor is used as the image sensor, there is no vertical line and there is only one horizontal line from the beginning. Therefore, all coordinate positions in the vertical line direction Y may be replaced with Y1. The normal measurement area has the coordinate position (X1, Y1) and the coordinate position (X2, Y1) as end points, and the normal measurement area is linear. Similarly, the follow-up measurement area is linear with the coordinate position (X3, Y1) and the coordinate position (X4, Y1) as endpoints.

  In the above embodiment, only one follow-up type measurement area is set, but two or more numbers may be set. Also, the direction may be either the horizontal line direction X and / or the vertical line direction Y. As such an example, it is assumed that two follow-up type measurement areas are set and the thickness of the transparent body is measured. For example, there is often a glass plate having a metal film on the back surface even if the surface is bare glass. As such a glass plate, a glass plate used for a cathode ray tube of a television, a glass plate of a liquid crystal display panel, and the like correspond. In order to measure such a glass plate with the sensor head part 2 of the displacement sensor, the displacement sensor of the present embodiment can execute the processing in the multi-region automatic tracking measurement mode as one of the automatic tracking measurement modes.

  Hereinafter, the multiple area automatic follow-up measurement process will be described with reference to the flowchart shown in FIG. 11 and the explanatory diagram shown in FIG. When the process shown in FIG. 11 is started, a process for setting a follow-up measurement area is executed (step 1101), and a normal measurement area is set.

  Subsequent to step 1101, a process for acquiring light receiving position data is executed (step 1102). The measurement area set in step 1101 is measured while thinning out one horizontal line X in the displacement measurement direction, for example, and a predetermined density value distribution (luminance distribution) is acquired.

  Subsequently, it is determined whether or not there is a light reception data area (step 1103). If there is a light reception data area, it is then determined whether there are a plurality of light reception data areas (step 1104). When there are a plurality of light reception data areas, a high-speed measurement process is executed between the areas (areas with the irradiated light image) (step 1105). That is, thinning measurement is performed over data arranged at predetermined intervals in the displacement measurement direction. In order to show the situation at this time, an example in the case where there are a plurality of light reception data areas is shown in FIG. As shown in FIG. 13, in the rectangular field of view Z, as the light reception data area, there are a back side irradiation light image “1” and a front side irradiation light image “2” corresponding to the front and back surfaces of the glass plate. The distance between the center line of the back-illuminated light image “1” and the center line of the front-illuminated light image “2” is measured as the thickness of the glass plate, and the measurement result is output (step 1106).

  Subsequent to Step 1106, a tracking measurement area is set for each of the back-surface irradiation light image “1” and the front-surface irradiation light image “2”, and measurement processing is executed in detail over all lines of the tracking-type measurement area. (Step 1107) and measurement results (eg, displacement, sensitivity, peak value, etc.) are output (Step 1108). Then, following step 1108, the process returns to step 1102 again.

  In step 1104, when there are not a plurality of light reception data areas, a tracking area measurement process (step 1109) for measuring a tracking measurement area provided for one light reception data area is executed, and a measurement result is output ( Step 1110).

  In step 1103, if there is no light reception data area, a measurement area other than the normal measurement area set in step 1101 is set, and a light reception position confirmation process for acquiring light reception position data is executed (step 1111). It is determined whether or not there is a light reception data area (step 1112). If there is a light reception data area, the process returns to step 1104. If there is no light reception data area, a measurement error output is executed (step 1113), and the process returns to step 1102.

  According to the above-described embodiment, even when the glass plate that is the thickness measurement target moves to the side / distant side of the sensor head unit 2, the measurement region is made to follow the displacement direction, and the measurement cannot be performed. It can be prevented beforehand.

  Needless to say, a case where a one-dimensional image sensor is used can be realized by the same replacement as described above.

  As described above, according to the displacement sensor device of the present embodiment, the position of the irradiation light image is detected from the distribution of the received light signal in the normal measurement region, and the normal measurement including the irradiation light image is performed based on the detection result. A tracking type measurement area narrower than the area is set, and measurement of the target displacement is executed only in this tracking type measurement area. For this reason, even if there is variation in the arrangement of the measurement target objects on the line, for example, the data necessary for the measurement is partially captured instead of capturing the data of the entire measurement region corresponding to the position change. Therefore, the time required for data reading and processing is shortened as compared with the conventional method by the small measurement area, and the response speed of the sensor is increased.

  Although the displacement sensor has been described in the above embodiment, the present invention is not limited to this and may be configured as a length measurement sensor or an angle sensor.

It is an external appearance perspective view of a signal processing part. It is an external appearance perspective view of the continuous state of a signal processing part. It is an external appearance perspective view of a sensor head part. It is a block diagram which shows the electrical hardware constitutions of a signal processing part. It is a block diagram which shows the electrical hardware constitutions of a sensor head part. It is a general flowchart which shows operation | movement of a signal processing part. It is a flowchart which shows the detail of a FUN mode process. It is a flowchart which shows the detail of a RUN mode process. It is a general flowchart which shows the process of automatic tracking measurement mode. It is a flowchart which shows the detail of a high-speed area | region automatic tracking measurement process. It is a flowchart which shows the detail of a multiple area | region automatic tracking measurement process. It is explanatory drawing of a high-speed area | region automatic tracking measurement mode. It is explanatory drawing of multiple area | region automatic tracking measurement mode. This is a thinned data density value distribution (horizontal line data). It is FIG. (1) for demonstrating the problem of a prior art. It is FIG. (2) for demonstrating the problem of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Signal processing part 2 Sensor head part 3 Relay connector 4 DIN rail 5 Measuring object 10 Outer shell case 11 External connection cord 12 USB connector 13 RS-232C connector 14 Operation part cover 15 Display part 16 Signal processing part connector cover 17 Sensor Connector for head section 20 Sensor head main body section 21 Cable 27 Connector for signal processing section connection L1 Slit light L2 Reflected light of slit light LM Irradiated light image of slit light 101 Control section 102 Storage section 102a EEPROM
102b Image memory 103 Display unit 103a Liquid crystal display unit 103b Indicator LED
104 communication unit 105 external communication unit 105a USB communication unit 105b serial communication unit 105c signal processing unit communication unit 106 key input unit 107 external input unit 108 output unit 109 power supply unit 110 personal computer 201 control unit 202 light projecting unit 203 light receiving unit 204 display LED
205 Storage unit 206 Communication unit

Claims (10)

A light projecting element for irradiating the measurement object with light at a predetermined angle;
An image sensor for photographing a measurement target object irradiated with light from another angle;
Normal measurement area setting means capable of setting a normal measurement area within the field of view of the image sensor;
Irradiation light image position detection means for detecting the position of the irradiation light image in the field of view of the image sensor by scanning the set normal measurement region;
Follow-up measurement area setting means for setting at least one follow-up measurement area that includes the position of the detected irradiation light image and is narrower than the normal measurement area in the displacement measurement direction;
A displacement measuring means for measuring a target displacement by measuring a tracking type measurement region;
An output device for outputting the measured displacement.   The irradiation light image position detection means measures the density value distribution of the received light signal in the field of view of the image sensor in the displacement measurement direction by performing decimation measurement over data arranged at predetermined intervals in the direction of displacement measurement of the image sensor. The sensor device according to claim 1, wherein the position of the irradiated light image is detected based on the density value distribution obtained. The light emitting element emits slit light,
The image sensor is a two-dimensional image sensor,
The irradiation light image position detection means measures the concentration value distribution of the received light signal in the displacement measurement direction for at least one line in the displacement measurement direction within the field of view of the two-dimensional image sensor, and based on the measured concentration value distribution, the irradiation light image The sensor device according to claim 1, wherein the position of the sensor is detected.   The density value distribution is measured by performing all line measurement over all data in the displacement measurement direction in the measurement region, or by performing thinning measurement over data arranged at a predetermined interval in the displacement measurement direction. Item 4. The sensor device according to Item 3.   The irradiation light image position detection unit measures the concentration value distribution of the received light signal in all directions in the displacement measurement direction in an area other than the normal measurement area in the field of view of the image sensor when no irradiation light image is detected in the normal measurement area. The sensor device according to claim 1, wherein thinning measurement is performed. The light emitting element emits slit light,
The image sensor is a two-dimensional image sensor,
The irradiation light image position detection means is a density value of the received light signal for at least one line in the displacement measurement direction in an area other than the normal measurement area within the field of view of the two-dimensional image sensor when no irradiation light image is detected in the normal measurement area. The sensor device according to claim 1, wherein the distribution is measured for all lines or thinned.   The measurement target object is a transparent body, two follow-up measurement areas are provided corresponding to the front and back surfaces of the transparent body, and measurement is performed by switching between the two follow-up measurement areas. Sensor device.   The thickness of the transparent body is measured by performing thinning measurement over data arranged at predetermined intervals in a displacement measurement direction connecting irradiation light images arranged in two tracking measurement regions. Sensor device.   The imaging device is configured by a CMOS imaging device, and the irradiation light image position detecting unit reads pixel data of a normal measurement region and a follow-up measurement region set directly from the CMOS imaging device. Sensor device.   The sensor device according to claim 1, wherein the sensor device is configured as a displacement sensor, a length measurement sensor, or an angle sensor.

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