JP6617068B2 - Substrate detection sensor - Google Patents

Description

  The present invention relates to a substrate detection sensor.

  Conventionally, a photoelectric sensor has a light projecting unit and a light receiving unit that are arranged to face each other with a detection region interposed therebetween, and outputs a detection signal according to the presence or absence of an object to be detected in the detection region based on the amount of light received by the light receiving unit. To do. For example, the photoelectric sensor is used as a substrate detection sensor that detects whether or not the substrate is in a predetermined position in a component mounting process of the substrate (see, for example, Patent Document 1).

  In the component mounting process of the substrate, the substrate is lifted from a predetermined position where the substrate is transported, and the component is mounted. When the mounting is completed, it is lowered to the transfer line and transferred to the next process. The substrate detection sensor confirms that the substrate has been transferred from the predetermined position to the next process.

JP 2009-302105 A

  By the way, when mounting an electronic component on a substrate, the substrate may be vibrated by moving the substrate when the substrate is raised or lowered, and the position in the transport direction may change unintentionally. In this case, since the amount of received light also varies, so-called chattering that repeats inversion of the determination result occurs.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a substrate detection sensor that can reduce erroneous determination with respect to substrate position fluctuations.

  A substrate detection sensor that solves the above problems is a substrate detection sensor that is provided in a transfer line on which a substrate is transferred and is arranged to detect the substrate on the transfer line, wherein the substrate is at a predetermined position. The substrate detection sensor is moved along a first direction orthogonal to the transport line, and the substrate detection sensor includes a light projecting unit and a light receiving unit disposed to face each other across the transport line, and the light receiving unit. A detection unit that detects the presence or absence of the substrate based on a light reception signal according to the amount of light received in the light source, and the light projecting unit sends a band-shaped light having a width in the first direction to the light receiving unit. The detection unit determines the presence or absence of the substrate by comparing the level of the received light signal with a first threshold value and a second threshold value greater than the first threshold value, and determines that there is no substrate. When receiving Compare the signal level with the first threshold, determine that the substrate is present when the level is less than or equal to the first threshold, and compare the level of the received light signal with the second threshold when determining that the substrate is present; When the level is equal to or higher than the second threshold, it is determined that there is no substrate.

  According to this configuration, when the detection unit that detects the presence / absence of the substrate determines that there is no substrate, the level of the light reception signal is compared with the first threshold, and if the level is equal to or lower than the first threshold, it is determined that the substrate is present. . When it is determined that there is a substrate, the level of the received light signal is compared with a second threshold value that is greater than the first threshold value. Thereby, after the determination of the presence of the substrate, the determination of the presence of the substrate is maintained even if the substrate fluctuates from a predetermined position due to vibration caused by the movement in the first direction, and the level of the received light signal rises or falls near the first threshold value. That is, by using two threshold values, chattering with respect to unintended position fluctuations of the substrate is less likely to occur than in the case of using one threshold value. Thereby, the erroneous determination with respect to the position fluctuation of the substrate can be reduced.

  In the substrate detection sensor, the first threshold value is used to position the substrate at a predetermined position, and the second threshold value is used to determine the presence / absence of the substrate transported by the transport line. It is preferable.

  According to this configuration, since the first threshold value is used to position the substrate at a predetermined position, the substrate can be positioned at the predetermined position. Further, since the second threshold value is used to determine the presence / absence of a substrate transported by the transport line, it can be determined whether the substrate has been transported by the transport line.

In the substrate detection sensor, it is preferable that a width of the band-shaped light is set larger than a movement amount of the substrate.
According to this configuration, since the width of the band-shaped light is set larger than the movement amount of the substrate, the substrate detection sensor detects the presence / absence of the substrate corresponding to the entire movement range of the substrate in the direction orthogonal to the transport line. Can be detected.

  In the substrate detection sensor, the detection unit sets a predetermined value as a reference level, sets the first threshold based on the reference level and a first ratio, and sets the second threshold as the reference level and the second ratio. It is preferable to set based on this.

  According to this configuration, the detection unit sets the first threshold value based on the reference level and the first ratio, and sets the second threshold value based on the reference level and the second ratio. Can be set easily.

In the substrate detection sensor, it is preferable that the detection unit sets the level of a light reception signal when the substrate is not present between the light projecting unit and the light receiving unit as the reference level.
According to this configuration, since the detection unit uses the level of the light reception signal when the substrate is not present between the light projection unit and the light reception unit as a reference level, the light from the light projection unit is blocked by the substrate. The level of the received light signal when the light is received by the light receiving unit can be set as the reference level.

In the substrate detection sensor, it is preferable that the detection unit has a setting function for setting the first ratio and the second ratio.
According to this configuration, since the detection unit has a setting function for setting the first ratio and the second ratio, the setting of the first ratio and the second ratio is changed with respect to a change in the size of the substrate or a predetermined position. This can be easily handled.

In the substrate detection sensor, the detection unit preferably sets the reference level based on an external trigger signal.
According to this configuration, since the detection unit sets the reference level based on an external trigger signal, the reference level can be set accurately. Thereby, the presence or absence of the substrate can be detected with higher accuracy.

In the substrate detection sensor, it is preferable that the detection unit has a setting function for setting whether the second threshold is valid or invalid.
According to this configuration, since the detection unit has a setting function for setting whether the second threshold is valid or invalid, it can be selected according to the substrate, the detection environment, and the like.

  The substrate detection sensor is used in a component mounting process for mounting an electronic component on the substrate, and a predetermined position where the substrate is moved along a direction orthogonal to the transfer line is a position at which the electronic component is mounted on the substrate. It is preferable that

  According to this configuration, the substrate detection sensor is used in a component mounting process for mounting an electronic component on the substrate, and the predetermined position where the substrate is moved is a position where the electronic component is mounted on the substrate. Thereby, it is possible to reduce misjudgment with respect to the position fluctuation in the board conveyance direction in the component mounting process.

  According to the substrate detection sensor of the present invention, it is possible to reduce erroneous determinations with respect to substrate position fluctuations.

(A)-(e) is a figure for demonstrating the component mounting process using a board | substrate detection sensor. The block diagram which shows schematic structure of a board | substrate detection sensor. Explanatory drawing of a controller. The flowchart which sets a 1st shift ratio. The flowchart which sets a 2nd shift ratio. The flowchart which sets the 1st and 2nd threshold value. (A)-(e) is explanatory drawing which shows the detection operation of a board | substrate detection sensor, (f) is a wave form diagram which shows a detection operation.

First, as a usage example of the board detection sensor, use in a component mounting process for mounting an electronic component on a board will be described.
As shown in FIG. 1A, the substrate W is transported by the transport device 31 toward a predetermined position A where the component mounting process is performed. At a predetermined position A, the light projecting unit 11 and the light receiving unit 12 of the substrate detection sensor 10 of the present embodiment are arranged to face each other with a transport device 31 that transports the substrate W interposed therebetween. The substrate detection sensor 10 of this embodiment is a transmissive photoelectric sensor that projects light from the light projecting unit 11 toward the light receiving unit 12. The light projecting unit 11 emits strip-shaped light (detection light) LW having a width set in a direction orthogonal to the transport direction of the substrate W, that is, in a direction perpendicular to the transport device 31.

  Then, as shown in FIG. 1B, when the substrate W reaches a predetermined position A, the amount of light received by the light receiving unit 12 decreases. The substrate detection sensor 10 has a controller 13 shown in FIG. The controller 13 compares the light reception signal Sr corresponding to the amount of light received by the light receiving unit 12 with a threshold value to determine whether the substrate W is present or not, which indicates whether the substrate W is at a predetermined position. . And the controller 13 outputs the signal (determination signal) according to the determination result. The transport device 31 stops transporting the substrate W based on the determination signal.

  The component mounting process includes a lift device (not shown). As shown in FIG. 1C, the lift device operates based on the determination signal, and moves (lifts) the substrate W to the mounting position. The mounting apparatus mounts an electronic component on the substrate W. After completion of the mounting, the lift device moves (drops) the substrate W onto the transfer device 31 as shown in FIG. The width of the band-shaped light (detection light) LW is larger than the movement amount of the substrate W. In other words, the amount of movement (the amount of increase and the amount of decrease) of the substrate W is smaller than the width of the strip-shaped light (detection light) LW. Then, as shown in FIG. 1E, the substrate W is transported to the next process by the transport device 31.

Next, an embodiment of the substrate detection sensor will be described.
As shown in FIG. 2, the substrate detection sensor 10 includes the light projecting unit 11, the light receiving unit 12, and the controller 13. The light projecting unit 11 and the light receiving unit 12 are connected to the controller 13 via optical fibers, respectively. The controller 13 includes a CPU 14, a light projecting circuit 15, and a light receiving circuit 16.

  The CPU 14 outputs a light projection signal Sg to the light projection circuit 15, and the light projection circuit 15 includes a light projection element, and causes the light projection element to emit light based on the light projection signal Sg. The light emitted from the light projecting element is sent to the light projecting unit 11 through the optical fiber, and band-shaped light (detection light LW) is emitted from the light projecting unit 11. The light received by the light receiving unit 12 is sent to the light receiving circuit 16 through an optical fiber. The light receiving circuit 16 includes a light receiving element, photoelectrically converts light received by the light receiving element, amplifies the converted signal, and outputs the amplified signal to the CPU 14. That is, the light receiving circuit 16 outputs a light receiving signal Sr (analog signal) at a level corresponding to the amount of light received by the light receiving unit 12 to the CPU 14. The CPU 14 compares the level L of the light receiving signal Sr output from the light receiving circuit 16 with a predetermined threshold value, and determines the presence or absence of the substrate W. For example, the CPU 14 samples the light reception signal Sr and performs analog-digital conversion to obtain a digital value (light reception level). The CPU 14 compares the received light level with a threshold value and determines the presence or absence of the substrate W.

  Here, the threshold value is a threshold value used for determining the presence or absence of the substrate W by being compared with the level L of the light reception signal Sr. The CPU 14 performs determination using the two threshold values of the first threshold value L1 and the second threshold value L2. For example, the CPU 14 determines whether or not the transported substrate W has reached a predetermined position (position A) based on the first threshold value L1. And CPU14 determines whether the board | substrate W was conveyed based on the 2nd threshold value L2. That is, the first threshold value L1 is used for positioning the substrate W at the position A, and the second threshold value L2 is used for determining the presence or absence of the substrate W at the position A.

  When the substrate W is not in the detection region, the level of the light reception signal Sr when received by the light receiving unit 12 is set to the reference level L0. The first threshold L1 is set to a value shifted from the reference level L0 by a predetermined dimming ratio (first shift ratio P1). Similarly, the second threshold L2 is set to a value shifted from the reference level L0 by a predetermined dimming ratio (second shift ratio P2). At this time, the second shift ratio P2 is set to a value larger than the first shift ratio P1. That is, the second threshold L2 is set to a value larger than the first threshold L1.

  For example, the first shift ratio P1 and the second shift ratio P2 are set as values of the ratio (percentage) with respect to the reference level L0. In the present embodiment, the first shift ratio P1 is 6 (%), and the second shift ratio P2 is 2 (%). In this case, the first threshold L1 is set to a value of 94 (%) of the reference level L0 based on the reference level L0 and the first shift ratio P1. The second threshold L2 is set to 98 (%) of the reference level L0 based on the reference level L0 and the second shift ratio P2. The first shift ratio P1 and the second shift ratio P2 can be set to arbitrary values in the setting mode described later.

  When the level L of the light reception signal Sr becomes smaller than the first threshold L1, that is, when the amount of light received by the light receiving unit 12 becomes small due to the presence of the substrate W, the CPU 14 moves the substrate W to the predetermined position A. It is determined that there is a “board” indicating that there is. Then, when the level L of the light reception signal Sr becomes larger than the second threshold value L2 from the state of determination of “substrate present”, that is, when the amount of light received by the light receiving unit 12 increases, the substrate W does not exist in the detection region. “No substrate” is determined. That is, the determination when inverting from “without substrate” to “with substrate” and the determination when inverting from “with substrate” to “without substrate” are different from each other (first and second thresholds L1, L2). ). Based on the determination result, the CPU 14 outputs a detection signal Sd at a level (for example, H level) corresponding to “with substrate” and a detection signal Sd at a level (for example, L level) corresponding to “without substrate”. Output to.

  As shown in FIG. 3, the controller 13 of the substrate detection sensor 10 of the present embodiment includes a display unit 18 that displays a plurality of functions and various set values provided in the substrate detection sensor 10, a mode selection switch 21, and an operation switch 22. And a switch input circuit 19 for outputting a signal to the CPU 14 based on the above operation. The operation switch 22 includes a confirmation key 22a, an up key 22b, and a down key 22c.

Next, modes provided in the substrate detection sensor 10 will be described.
The substrate detection sensor 10 sets, for example, a detection execution mode for executing the detection operation of the substrate W (output of the detection signal Sd), a teaching mode for setting the threshold values L1 and L2, and the shift ratios P1 and P2. And a setting mode. When any of the above modes is selected by operating the mode selection switch 21, processing related to the mode is allowed. At this time, the display of each mode on the display unit 18 is switched according to the operation of the mode selection switch 21.

When the confirmation key 22a is operated in a state where the detection execution mode is displayed on the display unit 18, the CPU 14 executes the detection operation of the substrate W (output of the detection signal Sd).
Further, when the enter key 22a is operated while the teaching mode is displayed on the display unit 18, the threshold value and the amount of received light are displayed on the display unit 18. In the teaching mode, for example, a plurality of functions including a threshold setting function for determining the reference level L0 by detecting the light reception signal Sr and setting the thresholds L1 and L2 based on the reference level L0 are provided. . Then, processing related to each setting function is allowed in accordance with the operation of the operation switch 22.

  When the enter key 22a is operated while the setting mode is displayed on the display unit 18, the function of the setting mode is displayed on the display unit 18. The setting mode has a plurality of setting functions (for example, a first setting function to a fifth setting function), and displays, for example, Pro1 to Pro5 on the display unit 18 corresponding to each setting function. The first setting function to the fifth setting function (Pro1 to Pro5) are switched and displayed on the display unit 18 according to the operation of the operation switch 22. Then, when the enter key 22a is operated in a state where any one of the first setting mode to the fifth setting mode is displayed, the processing related to the setting function is allowed. In the setting mode of the present embodiment, the first setting function (Pro1) is a first shift ratio setting function, and the second setting function (Pro2) is a second shift ratio setting function.

Next, each setting function executed by the CPU 14 will be described with reference to the flowcharts of FIGS.
[First shift ratio setting function]
In the first shift ratio setting function, a first shift ratio P1 for determining the first threshold value L1 is set.

  Specifically, after the setting mode is selected by the mode selection switch 21, when the first shift ratio setting function (Pro1) is displayed on the display unit 18 and the enter key 22a is pressed, the “first” shown in the flowchart of FIG. The “1 shift ratio setting routine” is executed.

  First, the currently set value of the first shift ratio P1 is displayed on the display unit 18 (step S1). At this time, when the up key 22b is pressed once (Yes in step S2), the value of the first shift ratio P1 is added (step S3), and the added value is displayed on the display unit 18 (step S3). S6). Conversely, when the down key 22c is pressed once (No in step S2 and Yes in step S4), the value of the first shift ratio P1 is subtracted (step S5) and subtracted on the display unit 18. A value is displayed (step S6). Thus, by operating the up key 22b or the down key 22c, the display value of the display unit 18 is changed to a desired first shift ratio P1. When the enter key 22a is operated (Yes in step S7), the first shift ratio P1 currently displayed on the display unit 18 is set (step S8).

[Second shift ratio setting function]
In the second shift ratio setting function, a second shift ratio P2 for determining the second threshold L2 is set.

  Specifically, after the setting mode is selected by the mode selection switch 21, when the second shift ratio setting function (Pro2) is displayed on the display unit 18 and the enter key 22a is pressed, the “first” shown in the flowchart of FIG. “2 shift ratio setting routine” is executed.

  First, the validity or invalidity of the second shift ratio P2 is selected (step S11). If invalid is selected, the routine is terminated. On the other hand, when valid is selected, the currently set second shift ratio P2 is displayed on the display unit 18 (step S12). Note that steps S13 to S19 after step S12 are the same routine as the first shift ratio setting routine, and thus description thereof is omitted.

[Threshold setting function]
In the threshold setting function, the reference level L0 of the light reception signal Sr is determined, and first and second thresholds L1 and L2 that are shifted from the reference level L0 by the first and second shift ratios P1 and P2 are set.

  Specifically, after the teaching mode is selected by the mode selection switch 21, when the threshold setting function is displayed on the display unit 18 and the enter key 22a is pressed, the “teaching routine” shown in the flowchart of FIG. 6 is executed. .

  First, it is determined whether or not the enter key 22a has been pressed (step S21). When operated (Yes in step S21), the level of the light reception signal Sr is sampled and stored as the reference level L0 (step S22). Further, the reference level L0 of the present embodiment is set by inputting a trigger signal to the input / output circuit 17 from the outside. The trigger signal is supplied from, for example, a controller that controls the component mounting process. The controller outputs a trigger signal to the substrate detection sensor 10 when the substrate W does not exist in the detection region, for example, at the start of the mounting process. The CPU 14 of the substrate detection sensor 10 performs a teaching operation based on the trigger signal and sets the reference level L0.

  Then, the currently set two shift ratios (first and second shift ratios P1 and P2) are called (step S23), and subsequently, whether the second shift ratio P2 is valid or invalid is determined (step S24). .

  When the second shift ratio P2 is valid (Yes in step S24), the first and second threshold values L1 and L2 are calculated based on a predetermined calculation formula including the reference level L0 and the shift ratios P1 and P2 (step S25). ) And the first and second threshold values L1 and L2, respectively (step S26). The calculation formula of this embodiment is as follows: L1 = L0−L0 × P1, L2 = L0 when the reference level L0, the first threshold L1, the second threshold L2, the first shift ratio P1, and the second shift ratio P2. -L0 × P2 is used.

  On the other hand, when the second shift ratio P2 is invalid (No in step S24), only the first threshold L1 is calculated based on the above calculation formula (step S27) and set as the first threshold L1 (step S28). . Although omitted in the flowchart of FIG. 6, when the second shift ratio P2 is invalid, the target object is based on the threshold value L1a (threshold value for hysteresis) set based on the first threshold value L1 and the first threshold value L1. The presence or absence of is determined. The threshold value L1a is set to a value (for example, a value that is 0.1% higher) than the first threshold value L1, for example. By setting the threshold value L1a having a small difference with respect to the first threshold value L1, the object can be detected with high accuracy.

Next, the detection operation of the substrate detection sensor will be described with reference to FIGS. 7 (a) to 7 (f).
As shown in FIG. 7A, the substrate W to be transferred does not reach the predetermined position A. The CPU 14 illustrated in FIG. 2 sets the first threshold value L1 as a threshold value for determination with respect to the light reception signal Sr. At this time, as shown in FIG. 7F, the light reception signal Sr is at the reference level L0 and is larger than the first threshold value L1, and therefore it is determined that there is no substrate. Based on the determination result, the detection signal Sd becomes L level.

  As shown in FIG. 7B, when the substrate W reaches a predetermined position A, a part of the detection light LW projected from the light projecting unit 11 is shielded by the substrate W. At this time, as shown in FIG. 7F, since the light reception signal Sr is lower than the first threshold value L1, it is determined that there is a substrate. Based on the determination result, the detection signal Sd becomes H level. Then, the CPU 14 shown in FIG. 2 changes the threshold value for determination from the first threshold value L1 to the second threshold value L2.

  As shown in FIG. 7C, when the detection signal Sd becomes H level, the conveyance is interrupted, the substrate W is lifted to the mounting position by a lift device (not shown), and the electronic component is mounted. When the mounting is completed, the substrate W is lowered onto the transfer device 31 as shown in FIG. At this time, the position of the substrate W fluctuates from the predetermined position A due to ascent and descent by the lift device. Therefore, as shown in FIG. 7F, the light reception signal Sr becomes higher or lower than the first threshold value L1, that is, the light reception signal Sr is in an unstable state. At this time, the CPU 14 sets the second threshold L2 as a threshold for determination. The second threshold L2 is set to a value close to the reference level L0 (for example, 98% of the reference level L0). Accordingly, since the fluctuation of the light reception signal Sr is not so large that the second threshold value L2 is reached, the determination of “with substrate” is maintained. Therefore, the detection signal Sd also remains at the H level.

  As shown in FIG. 7E, when the substrate W is returned onto the transfer device 31, it is transferred to the next process. At this time, as shown in FIG. 7F, the light reception signal Sr rises to the reference level L0. Accordingly, since the light reception signal Sr is higher than the second threshold value L2, it is determined that “no substrate”. Based on the determination result, the detection signal Sd becomes L level.

  As described above, the substrate detection sensor 10 according to the present embodiment compares the level L of the light reception signal Sr with the first threshold L1 when it is determined that “no substrate”, and when the level L becomes equal to or less than the first threshold L1, It is determined as “Yes”. When it is determined that “substrate is present”, the level L of the light reception signal Sr is compared with a second threshold L2 that is larger than the first threshold L1, and when the level L is equal to or less than the second threshold L2, it is determined that “substrate is absent”. Thus, even after the determination of “with substrate”, even if the substrate W fluctuates from the predetermined position A due to vibration due to rising and lowering, and the level L of the light reception signal Sr fluctuates around the first threshold value L1, it is “with substrate”. Judgment is maintained. That is, in the substrate detection sensor 10 according to the present embodiment using the two threshold values L1 and L2, chattering with respect to unintended position variation of the substrate W is less likely to occur than when using one threshold value. Further, the difference between the values of the first and second threshold values L1 and L2 is set to be sufficiently larger than the difference for the purpose of only suppressing chattering. Therefore, the inversion from “with substrate” to “without substrate” is performed. More accurate determination can be made.

  The substrate detection sensor 10 of the present embodiment sets the received light amount when the detection target (substrate W) is not present between the light projecting unit 11 and the light receiving unit 12 as the reference level L0. The first threshold L1 is set to a value lower than the reference level L0 based on the first shift ratio P1. The first shift ratio P1 is set based on, for example, fluctuations in the amount of received light. For this reason, for example, when a foreign object other than the detection target passes between the light projecting unit 11 and the light receiving unit 12, the light reception signal Sr does not become lower than the first threshold L1. For this reason, it is possible to prevent erroneous determination of “there is a substrate” due to fluctuations in the amount of received light due to foreign matter or the like.

  Further, the second threshold L2 is set to a value close to the reference level L0 based on the second shift ratio P2. For this reason, even if the unintended fluctuation of the light reception signal Sr occurs due to the movement of the substrate W, the light reception signal Sr is unlikely to be larger than the second threshold L2. For this reason, it is possible to suppress the occurrence of erroneous determination with respect to a change in the light reception signal Sr based on the movement of the substrate W.

Next, the effect of this embodiment will be described.
(1) The CPU 14 that detects the presence or absence of the substrate W compares the level L of the light reception signal Sr with the first threshold value L1 when determining that there is no substrate, and when the level L becomes equal to or less than the first threshold value L1, It is determined that there is a board. When it is determined that “substrate is present”, the level L of the light reception signal Sr is compared with a second threshold L2 that is greater than the first threshold L1, and when the level L is equal to or greater than the second threshold L2, it is determined that “substrate is absent”. As a result, even if the substrate W fluctuates from the predetermined position A due to vibration due to movement (up / down) after the determination of “substrate is present” and the level L of the light reception signal Sr fluctuates around the first threshold value L1, the “substrate” The determination “Yes” is maintained. That is, by using the two threshold values L1 and L2, chattering with respect to unintended positional fluctuations of the substrate W is less likely to occur than when using one threshold value. Thereby, the erroneous determination with respect to the position fluctuation | variation of the board | substrate W can be reduced.

  (2) Since the first threshold value L1 is used to position the substrate W at the predetermined position A, the substrate W can be positioned at the predetermined position A. Further, since the second threshold value L2 is used to determine the presence / absence of the substrate W transported by the transport device 31, it is possible to determine whether or not the substrate W is transported by the transport device 31.

  (3) Since the width of the detection light LW in the direction orthogonal to the transport direction of the substrate W is set to be larger than the movement amount of the substrate W, the substrate detection sensor 10 has the entire movement (up / down) range of the substrate W. The presence or absence of the substrate W can be detected corresponding to the above.

  (4) Since the CPU 14 sets the first threshold L1 based on the reference level L0 and the first ratio P1, and sets the second threshold L2 based on the reference level L0 and the second ratio P2, the first threshold L1 and The second threshold L2 can be easily set.

  (5) Since the CPU 14 sets the level L of the light reception signal Sr when the substrate W is not present between the light projecting unit 11 and the light receiving unit 12 as the reference level L0, the detection light LW from the light projecting unit 11 is the substrate. The level L of the light reception signal Sr when received by the light receiving unit 12 without being shielded by W can be set to the reference level L0.

  (6) Since the CPU 14 has a setting function for setting the first ratio P1 and the second ratio P2, the first ratio P1 and the second ratio P2 are set in response to a change in the size of the substrate W or the predetermined position A. It is possible to easily cope with the change.

  (7) Since the CPU 14 sets the reference level L0 based on an external trigger signal, the CPU 14 can set the reference level L0 accurately. Thereby, the presence or absence of the substrate W can be detected with higher accuracy.

(8) Since the CPU 14 has a setting function for setting whether the second threshold L2 is valid or invalid, it can be selected according to the substrate W, the detection environment, and the like.
(9) The substrate detection sensor 10 is used in a component mounting process for mounting an electronic component on the substrate W, and the predetermined position A where the substrate W is moved is a position where the electronic component is mounted on the substrate W. Thereby, it is possible to reduce misjudgment with respect to a positional variation in the conveyance direction of the substrate W in the component mounting process.

In addition, you may change the said embodiment as follows.
In the above embodiment, the board detection sensor 10 is used in the component mounting process of the board W, but may be used in other processes.

  In the above embodiment, the reference level L0 of the light reception signal Sr is the level of the light reception signal Sr in a state where the substrate W does not exist in the detection region, but the state of setting the reference level L0 may be changed as appropriate.

  In the above embodiment, the second shift ratio P2 is set to be valid or invalid by the second shift ratio setting function. However, the second threshold L2 may be valid or invalid in the teaching routine of the threshold setting function. Good.

  In the above embodiment, the first threshold value L1 and the second threshold value L2 are set with the first shift ratio P1 being 6% and the second shift ratio P2 being 2%, but the values of the first and second shift ratios P1 and P2 are set. May be appropriately changed in accordance with a change in the size of the substrate W or a predetermined position A where the component mounting process is performed.

The number of modes of the CPU 14 and the number of functions in the setting mode are not limited to the above embodiment, and may be changed as appropriate.
The calculation formula used in the threshold setting function is not limited to the above embodiment, and may be changed as appropriate.

-The aspect of selection operation of the board | substrate detection sensor 10 is not limited to the said embodiment, You may change suitably according to a structure.
In the embodiment described above, the level of the detection signal Sd may be changed as appropriate. For example, when it is determined that “substrate is present” based on the first threshold value L1, the L level detection signal Sd is output.

  DESCRIPTION OF SYMBOLS 10 ... Board | substrate detection sensor, 11 ... Light projection part, 12 ... Light-receiving part, 14 ... CPU (detection part), L ... Level, L0 ... Reference level, L1 ... 1st threshold value, L2 ... 2nd threshold value, P1 ... 1st Shift ratio (first ratio), P2 ... second shift ratio (second ratio), Sr ... light reception signal, W ... substrate, A ... predetermined position, LW ... detection light (band-like light).

Claims (9)

A substrate detection sensor provided in a conveyance line to which a substrate is conveyed and arranged to detect the substrate on the conveyance line,
The substrate is moved along a first direction orthogonal to the transport line at a predetermined position;
The substrate detection sensor includes a light projecting unit and a light receiving unit that are arranged opposite to each other in the horizontal direction across the transport line, and a detection unit that detects the presence or absence of the substrate based on a light reception signal corresponding to the amount of light received by the light receiving unit And comprising
The light projecting unit emits band-shaped light having a width in the first direction toward the light receiving unit,
The detection unit determines the presence or absence of the substrate by comparing the level of the light reception signal with a first threshold value and a second threshold value greater than the first threshold value, and determines the level of the light reception signal when determining that there is no substrate. Is compared with the first threshold value. When the level falls below the first threshold value, it is determined that there is a substrate, and when it is determined that there is a substrate, the level of the light reception signal is compared with the second threshold value. Determining that there is no substrate when the second threshold value is exceeded;
A substrate detection sensor.   The first threshold value is used to position the substrate at a predetermined position, and the second threshold value is used to determine whether or not the substrate is transported by the transport line. Item 8. The substrate detection sensor according to Item 1.   3. The substrate detection sensor according to claim 1, wherein a width of the band-shaped light is set larger than a movement amount of the substrate.   The detection unit sets a predetermined value as a reference level, sets the first threshold based on the reference level and the first ratio, and sets the second threshold based on the reference level and the second ratio. The board | substrate detection sensor of any one of Claims 1-3 characterized by the above-mentioned.   The substrate detection sensor according to claim 4, wherein the detection unit sets a level of a light reception signal when the substrate is not present between the light projecting unit and the light receiving unit as the reference level.   The substrate detection sensor according to claim 4, wherein the detection unit has a setting function for setting the first ratio and the second ratio.   The substrate detection sensor according to claim 4, wherein the detection unit sets the reference level based on an external trigger signal.   The substrate detection sensor according to claim 1, wherein the detection unit has a setting function for setting whether the second threshold is valid or invalid.   A predetermined position used in a component mounting process for mounting an electronic component on the substrate and moved along a direction orthogonal to the transport line is a position for mounting the electronic component on the substrate. The substrate detection sensor according to claim 1.

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