JP7589602B2 - Sensor Device - Google Patents

Description

The present invention relates to a sensor device equipped with a light-emitting unit and a light-receiving unit.

A component mounting device that mounts (mounts) electronic components on a substrate such as a printed wiring board to produce an electronic circuit board is equipped with a tape feeder. The tape feeder supplies electronic components by intermittently feeding out a carrier tape containing electronic components from a reel on which the carrier tape is wound. The carrier tape is transported on a tape passage made of aluminum or the like provided in the tape feeder.

Multiple carrier tapes are wound around the reel and connected longitudinally using splicing tape. Therefore, there are seams in the carrier tape being transported, and the seams are detected in order to manage the carrier tape lot.

One method for detecting seams is to detect the presence or absence of a feed hole on the side of the carrier tape. At seams in the carrier tape, the splicing tape covers the hole, so a sensor detects the absence of a hole and determines that there is a seam.

Also, as shown in Patent Document 1, a detection sensor is known that detects a surrounding physical quantity as a received signal, discriminates the received signal using a threshold value, and identifies whether the physical quantity is on or off.

Japanese Patent Application Publication No. 7-221623

However, the method of detecting the seams of the carrier tape to determine whether there are any fitting holes has the problem that if the carrier tape meanders, the sensor cannot detect the fitting holes, and therefore the seams cannot be detected.

One aspect of the present invention aims to provide a sensor device that can detect the seams of transported goods with greater accuracy.

In order to solve the above problems, a sensor device according to one aspect of the present invention has the following configuration.

That is, the sensor device according to one aspect of the present invention includes a light-projecting unit that projects light, a light-receiving unit that detects the amount of reflected light received from an irradiation area of the light projected from the light-projecting unit, an acquisition unit that acquires color information of an object present in the irradiation area from the amount of received light, a seam detection unit that detects seams of the transported object by comparing the acquired color information with a reference value acquired in advance for the transported object transported in the irradiation area, a leading edge detection unit that detects the arrival of the leading edge of the transported object in the irradiation area by comparing the detected amount of received light with a passage detection threshold set based on the amount of received light detected when the passage for transporting the transported object is present in the entire irradiation area, a calculation unit that calculates the waiting time from the time the arrival of the leading edge is detected to the time the reference value is acquired using the transport speed of the transported object, and a setting unit that sets the color information acquired at that time as the reference value when the waiting time has elapsed since the arrival of the leading edge was detected.

According to the above configuration, the seam of the transported object is detected based on the difference between the color information of the transported object and the color information of the seam. This allows the seam to be detected more accurately than with conventional methods. Furthermore, according to the above configuration, when it is detected that the leading edge of the transported object has arrived, the setting unit automatically acquires a reference value to be used for detecting the seam. This eliminates the need to visually set the reference value, improving the convenience of the sensor device.

Moreover, according to the above configuration, the calculation unit calculates the waiting time using the transport speed of the transported object. The waiting time is a factor that determines the timing for acquiring and setting the reference value from the point in time when the leading edge of the transported object is detected by the leading edge detection unit, and if the waiting time is short, there is a risk that the reference value will be set based on the amount of light received when the transported object has not entered the entire irradiation area. By using the waiting time calculated from the transport speed as in the above configuration, it is possible to always set the reference value accurately.

In the sensor device according to the above aspect, the calculation unit may be configured to calculate the waiting time using the conveying speed and the length of the irradiation area in the conveying direction.

According to the above configuration, since the length of the irradiation area in the transport direction is used in addition to the transport speed, it is possible to calculate the waiting time more accurately, and it is possible to always set the reference value accurately.

In the sensor device according to the above aspect, the passage detection threshold may be set to a first threshold higher than the amount of received light and a second threshold lower than the amount of received light based on the amount of received light detected when the passage is present in the entire illumination area.

With the above configuration, it is possible to detect the arrival of the leading edge of the transported object even if the color of the transported object reflects more light than the passageway, or conversely, even if the color reflects less light.

In the sensor device according to one aspect described above, the transported object may be a carrier tape on which a plurality of components are mounted in a row along the longitudinal direction, and may have a seam portion connected in the longitudinal direction by a connecting tape.

According to one aspect of the present invention, it is possible to provide a sensor device that can detect the seam of a transported object with greater accuracy.

2 is a schematic diagram showing a configuration of a tape feeder on which a color sensor according to the embodiment is mounted. FIG. FIG. 2 is a plan view of a carrier tape applied to the tape feeder. 4 is a schematic diagram showing the relationship between a tape path in the tape feeder, a color sensor, and a carrier tape transported along the tape path. FIG. FIG. 2 is an exploded perspective view showing the configuration of a color sensor according to the embodiment. 2 is a block diagram showing a configuration of a color sensor according to the embodiment; FIG. 13 is a diagram showing the change in the amount of received light from a state in which no carrier tape is present in the irradiation area of the light projector to a state in which the carrier tape is present in the entire irradiation area. This figure shows the change in the degree of mismatch from a state in which no splicing tape is present in the illumination area of the light projector to a state in which the splicing tape is present in the entire illumination area. 5 is a flowchart showing the operation of the color sensor according to the embodiment. 9 is a flowchart illustrating a continuation of FIG. 8 .

Below, an embodiment according to one aspect of the present disclosure (hereinafter also referred to as the present embodiment) will be described with reference to the drawings. In this embodiment, a color sensor 1 mounted on a tape feeder that feeds out a carrier tape will be illustrated as one aspect of the sensor device of the present disclosure.

§1 Application Example First, an example of a situation in which the color sensor 1, which is a sensor device, is applied will be described with reference to Figs. 1, 3, and 5 to 7. As shown in Fig. 1, the color sensor 1 is mounted on, for example, a tape feeder 100, and detects a seam portion in the carrier tape 10 transported through a tape passage 104. As shown in Fig. 3, the carrier tape 10 is spliced by a splicing tape 15. The seam detection unit (see Fig. 5) compares the previously acquired reference value of the RDB value of the carrier tape 10 with the acquired RGB value, and obtains the degree of mismatch, which is the difference in color, as shown in Fig. 7. Then, the splicing tape 15 is detected based on the degree of mismatch to detect the seam portion. As a result, compared to a method of detecting a state in which the fitting hole 12 is blocked, the seam portion can be detected without any problem even if the carrier tape 10 meanders.

The leading edge detection unit 25 (see FIG. 5) detects the leading edge of the carrier tape by comparing the amount of received light with the path detection threshold, as shown in FIG. 6. When the leading edge is detected, the reference value setting unit 26 (see FIG. 5) sets the RGB values after a predetermined waiting time has elapsed since the leading edge was detected as the reference values used for detecting the splicing tape 15. This allows the reference value to be set automatically, improving the convenience of the color sensor 1. Moreover, since the calculation unit (see FIG. 5) calculates the waiting time using the transport speed of the carrier tape 10, it is possible to always set the reference value accurately.

§2 Configuration Example (1. Tape Feeder 100)
Fig. 1 is a schematic diagram showing the configuration of a tape feeder 100 on which a color sensor 1 according to this embodiment is mounted. As shown in Fig. 1, the tape feeder 100 is an autoloading tape feeder that supplies components such as electronic components using a carrier tape 10. The tape feeder 100 includes a main body 101 that is elongated in the front-rear direction. The tape feeder 100 further includes a first feed section 102, a second feed section 103, a tape passage 104, the color sensor 1 according to this embodiment, and a control section (not shown).

The first feed section 102 is provided at the front end of the main body 101, and the second feed section 103 is provided at the rear end of the main body 101. The first feed section 102 and the second feed section 103 feed the carrier tape 10 in a direction from the rear end to the front end of the main body 101. The tape passage 104 is a passage for guiding the carrier tape 10 provided in the main body 101, and is made of, for example, aluminum. The carrier tape 10 is transported along the tape passage 104 by the first feed section 102 and the second feed section 103. In the configuration of FIG. 1, the carrier tape 10 is introduced into the inside of the main body 101 from the rear end of the main body 101, and is guided to the front of the upper surface of the main body 101 through the tape passage 104.

The color sensor 1 is disposed facing the tape passage 104 so that light from the light projecting unit 2, which will be described later, is projected onto the tape passage 104. The color sensor 1 detects the seam portion of the carrier tape 10 transported along the tape passage 104. In this embodiment, the color sensor 1 automatically acquires a reference value used to detect the seam portion when it detects that the leading end of the carrier tape 10 has reached the irradiation area (detection area) of the light projecting unit 2. The color sensor 1 will be described in detail later.

The control unit controls each part of the tape feeder 100. Various information and signals are exchanged between the control unit of the tape feeder 100 and a determination unit 4 (described later) provided in the color sensor 1. The tape feeder 100 and the color sensor 1 are in a master-slave relationship.

(2. Carrier Tape 10)
The carrier tape 10 applied to the tape feeder 100 will be described with reference to Fig. 2 and Fig. 3. Fig. 2 is a plan view of the carrier tape 10 applied to the tape feeder 100. Fig. 3 is a schematic diagram showing the relationship between the tape path 104 in the tape feeder 100, the color sensor 1, and the carrier tape 10 transported through the tape path 104.

As shown in FIG. 2, the carrier tape 10 is a strip-shaped tape, and on one surface 10A in the thickness direction, multiple recessed component storage sections 11 for storing components 13 are arranged in a row along the longitudinal direction. On one side in the width direction of the component storage sections 11, multiple fitting holes 12 are provided that are arranged at regular intervals in the longitudinal direction. The fitting holes 12 are provided penetrating the carrier tape 10 in its thickness direction. The carrier tape 10 is loaded into the tape feeder 100 with the back surface opposite the surface 10A facing the tape passage 104. Such carrier tapes 10 are available in different colors, such as white, black, gray, and transparent.

As shown in FIG. 3, the longitudinal ends of the carrier tape 10 are connected with a splicing tape 15, which is a connecting tape. The splicing tape 15 also comes in different colors, such as blue, light blue, yellow, and black.

(3. Color Sensor 1)
Fig. 4 is an exploded perspective view showing the configuration of the color sensor 1 according to this embodiment. As shown in Fig. 4, the color sensor 1 includes a light projecting unit 2, a light receiving unit 3, a determination unit 4, a substrate 5, a case 6, a lens unit 7, and a cover 8.

The light-projecting unit 2 projects light, and the light-receiving unit 3 detects the amount of light reflected from the irradiation area of the light projected from the light-projecting unit 2. The light-projecting unit 2 includes a light-projecting element such as a white LED (light-emitting diode), and a light-projecting circuit. The light-receiving unit 3 includes light-receiving elements for each of the RGB wavelength regions, such as a PTR (phototransistor) or a PD (photodiode), and a light-receiving circuit. The light-receiving circuit includes an amplifier circuit that amplifies an electrical signal according to the amount of light received by the light-receiving element, an A/D converter, etc.

In addition, in the light receiving unit 3, a single light receiving element may be used to detect achromatic and chromatic colors, or two light receiving elements may be provided to separately detect achromatic and chromatic colors.

The determination unit 4 detects the splicing tape 15 based on the amount of light received by the light receiving unit 3, thereby detecting the joint portion of the carrier tape 10. It also detects the presence or absence of the carrier tape 10 on the tape passage 104, and automatically obtains a reference value used to detect the splicing tape 15 when it detects that the tip of the carrier tape 10 has reached the irradiation area. Details of the determination unit 4 will be described later.

The light-projecting unit 2, the light-receiving unit 3, and the determination unit 4 are mounted on the board 5. The case 6 is a support member that supports the board 5 and the lens unit 7. The lens unit 7 is attached to the bottom surface of the case 6, and the board 5 is installed inside the case 6 so that the surface on which the light-projecting unit 2 and the light-receiving unit 3 are mounted faces downward. The lens unit 7 is a light-projecting and light-receiving lens, and has a lens that controls the beam of light projected from the light-projecting element, and a lens that collects light reflected from the irradiation area onto the light-receiving element. The cover 8 is a light-blocking member that blocks the opening at the top of the case 6 to prevent the intrusion of external light and dust.

(4. Determination Unit 4)
Fig. 5 is a block diagram showing the configuration of the color sensor 1 according to this embodiment. As shown in Fig. 5, the determination unit 4 includes a light projection control unit 21, an RGB value acquisition unit 22, a storage unit 23, a seam detection unit 24, a tip detection unit 25, a reference value setting unit 26, and a calculation unit 29. The determination unit 4 is formed of a computer device including, for example, a CPU (Central Processing Unit) or a dedicated processor.

The light projection control unit 21 controls the driving of the light projection unit 2. Under the control of the light projection control unit 21, the light projection circuit drives the light emitting element based on a predetermined pulse signal and irradiates light toward the tape path 104. The reflected light from an object present in the irradiation area is received by the light receiving element of the light receiving unit 3 and input to the RGB value acquisition unit 22 and the tip detection unit 25 via the light receiving circuit.

The RGB value acquisition unit (acquisition unit) 22 acquires RGB values, which are color information of objects present in the irradiation area, based on the amount of received light input via the light receiving circuit. The RGB value acquisition unit 22 sends the acquired RGB values to the seam detection unit 24.

The seam detection unit 24 compares the RGB values input from the RGB value acquisition unit 22 with the reference values (reference RGB values) of the carrier tape 10 acquired in advance to detect the seam portion of the carrier tape 10. In other words, the seam detection unit 24 detects the splicing tape 15. When the seam detection unit 24 detects the splicing tape 15, it notifies the output unit 27 of the detection, and in response, the output unit 27 notifies the outside that a seam portion has been detected.

In this embodiment, as described below, a seam detection threshold is set for detecting the splicing tape 15. The seam detection unit 24 detects the splicing tape 15 by comparing the degree of mismatch between the input RGB values and the reference value with the seam detection threshold. The reference value of the carrier tape 10 and the seam detection threshold are stored in the memory unit 23.

The leading edge detection unit 25 compares the amount of light received through the light receiving circuit with the path detection threshold to detect that the leading edge of the carrier tape 10 has reached the illuminated area. The path detection threshold is set based on the amount of light received that is detected when the tape path is present throughout the illuminated area, and is stored in the memory unit 23.

The calculation unit 29 uses the transport speed of the carrier tape 10 to calculate the waiting time from the time when the tip detection unit 25 detects that the tip of the carrier tape 10 has arrived until the reference value is acquired. In this embodiment, the calculation unit 29 calculates the waiting time using the transport speed of the carrier tape 10 and the length of the irradiation area in the transport direction.

For example, when the spot diameter corresponding to the irradiation area of the light projected from the light projecting element is 2 mm and the transport speed is 100 mm/msec, the calculation unit 29 calculates the waiting time as 2 (mm)/100 (mm/msec) = 20 msec. As another example, when the spot diameter is 2 mm and the transport speed is 5 mm/msec, the calculation unit 29 calculates the waiting time as 2 (mm)/5 (mm/msec) = 400 msec. As yet another example, when the spot diameter is 5 mm and the transport speed is 5 mm/msec, the calculation unit 29 calculates the waiting time as 5 (mm)/5 (mm/msec) = 1000 msec. The transport speed of the carrier tape 10 is input from the tape feeder 100 to the determination unit 4 via the input/output unit 28 and stored in the memory unit 23.

The reference value setting unit (setting unit) 26 sets a reference value of the carrier tape 10 used by the seam detection unit 24. When the waiting time calculated by the calculation unit 20 has elapsed since the tip detection unit 25 detected the arrival of the tip of the carrier tape 10, the reference value setting unit 26 sets the color information acquired by the RGB value acquisition unit 22 at that time as a reference value. The set reference value is stored in the memory unit 23. The waiting time used by the reference value setting unit 26 is also stored in the memory unit 23.

The memory unit 23 includes a seam detection threshold table, a passage detection threshold table, a conveying speed storage unit, and a reference value storage unit. Values can also be input to the memory unit 23 from the outside via the input/output unit 28.

The seam detection threshold table stores seam detection thresholds used by the seam detection unit 24. In this embodiment, two seam detection thresholds are set, a chromatic color threshold and an achromatic color threshold, to accommodate splicing tapes 15 of different colors (see FIG. 7).

The path detection threshold table stores the path detection threshold used by the tip detection unit 25. As described above, the path detection threshold is set based on the amount of received light detected when the tape path 104 is present throughout the entire irradiation area. The path detection threshold is a value that can determine that the tape path 104 is not present throughout the entire irradiation area, that is, that the carrier tape 10 is included in part of the irradiation area. In this embodiment, a first threshold higher than the amount of received light and a second threshold lower than the amount of received light are set based on the amount of received light detected when the tape path 104 is present throughout the entire irradiation area.

The conveying speed storage unit stores the conveying speed of the carrier tape 10 that is input from the tape feeder 100 and used by the calculation unit 29. The conveying speed is rewritten each time it is input from the tape feeder 100.

The reference value storage unit stores the reference value set by the reference value setting unit 26. The reference value is set and automatically rewritten each time the leading edge detection unit 25 detects the arrival of the leading edge of the carrier tape 10.

(5. Setting the Reference Value)
The setting of the reference value will be described with reference to Fig. 6. Fig. 6 is a diagram showing the change in the amount of received light from a state in which the carrier tape 10 is not in the irradiation area of the light projector 2 until the carrier tape 10 is in the entire irradiation area. As shown in Fig. 6, in section A where the leading end of the carrier tape 10 has not yet reached the irradiation area, the light receiver 3 detects the amount of received light L of reflected light from the tape path 104.

When the tip of the carrier tape 10 reaches the illuminated area, the amount of received light starts to increase from that point on. Section B where the amount of received light increases is the section where the tip of the carrier tape 10 is moving through the illuminated area. When the carrier tape 10 enters the entire illuminated area, the increase stops and the amount of received light levels off at H. Section C where the amount of received light levels off at H is the section where the reflected light from the carrier tape 10 is stably detected.

The passage detection threshold is set to a value between the amount of received light L and the amount of received light H. In the example of FIG. 6, it is set to a value slightly higher than the median value of section B. FIG. 6 shows an example in which the carrier tape 10 is white, etc., and the amount of reflected light is greater than that of the tape passage 104. Although not shown, the carrier tape 10 may be black or gray, etc., and the amount of reflected light may be less than that of the tape passage 104. In that case, the detected amount of received light begins to decrease when the tip of the carrier tape 10 enters the irradiation area, and becomes lower than the amount of received light L. Therefore, as described above, the passage detection threshold is set to a first threshold higher than the amount of received light L detected in section A, and a second threshold lower than the amount of received light L. The passage detection value shown in FIG. 6 corresponds to the first threshold.

As shown in FIG. 6, when the leading edge detection unit 25 detects the arrival of the leading edge of the carrier tape 10, the irradiation area still includes the tape passage 104. Therefore, to obtain the reference value, it is necessary to wait from the time when the leading edge is detected until the carrier tape 10 enters the entire irradiation area. This waiting time is the waiting time. If the waiting time is short, there is a risk that the reference value will be set based on the amount of light received when the transported object has not yet entered the entire irradiation area. If the waiting time is long, the setting of the reference value will be delayed.

In this embodiment, the calculation unit 29 sets the waiting time according to the transport speed of the carrier tape 10, so that it is possible to always set an appropriate waiting time without it being too short or too long, and thus to set an accurate reference value.

(6. Detection of splicing tape 15)
Detection of the splicing tape 15 will be described with reference to Fig. 7. Fig. 7 is a diagram showing the change in the degree of mismatch from a state in which the splicing tape 15 is not in the irradiation area of the light projector 2 until the splicing tape 15 is in the entire irradiation area. As shown in Fig. 7, in a section D in which the tip of the splicing tape 15 has not reached the irradiation area, the light receiver 3 detects the amount of reflected light received from the carrier tape 10, so that the degree of mismatch D0 between the acquired RGB value and the reference value is small.

When the tip of the splicing tape 15 reaches the illuminated area, the degree of mismatch begins to increase from that point on. Section D, where the amount of received light increases, is the section where the tip of the splicing tape 15 is moving through the illuminated area. When the splicing tape 15 enters the entire illuminated area, the increase stops, and in the example of Figure 7, the degree of mismatch levels off at D1 and D2.

The degree of mismatch D1 is the degree of mismatch between the RGB values based on the amount of light received by the achromatic splicing tape 15 and the reference value. The degree of mismatch D2 is the degree of mismatch between the RGB values based on the amount of light received by the chromatic splicing tape 15 and the reference value. When the splicing tape 15 is chromatic, the degree of mismatch is higher than when the splicing tape 15 is achromatic.

Two types of seam detection thresholds are set, a chromatic threshold and an achromatic threshold, to correspond to the color variations of the chromatic and achromatic splicing tape 15. By setting two types, it is possible not only to detect the splicing tape 15, but also to detect whether the splicing tape 15 is achromatic or chromatic.

If the splicing tape 15 is determined to have either a chromatic color threshold or an achromatic color threshold, the corresponding threshold is set as the seam detection threshold. By setting an achromatic color threshold, it is possible to handle both achromatic and chromatic splicing tapes 15.

(7. Operation of Color Sensor 1)
The operation of the color sensor 1 will be described with reference to Fig. 8 and Fig. 9. Fig. 8 is a flowchart showing the operation of the color sensor 1 according to this embodiment. Fig. 9 is a flowchart continuing from Fig. 8. The color sensor 1 starts its operation at the timing when the tape feeder 100 starts transporting the carrier tape 10, for example.

As shown in FIG. 8, at the start of operation, the determination unit 4 reads values from the memory unit 23 and sets the aisle detection threshold in the leading edge detection unit 25, the transport time in the calculation unit 29, and the seam threshold in the seam detection unit 24 (S1). Next, the calculation unit 29 calculates the waiting time using the transport time and the length of the irradiation area in the transport direction (S2).

Next, the determination unit 4 starts detecting the amount of light projected by the light projector 2 and the amount of light received by the light receiver 3 (S3). When the amount of received light is input, the tip detector 25 determines whether the amount of received light exceeds the passage detection threshold (S4). If the light receiver 3 has multiple light receiving elements, it determines whether the sum of the amounts of received light exceeds the passage detection threshold. The tip detector 25 repeats S4 until it determines that the amount of received light exceeds the passage detection threshold.

If it is determined in S4 that the amount of received light has exceeded the passage detection threshold, the leading edge detection unit 25 notifies the reference value setting unit 26 that the leading edge of the carrier tape 10 has been detected (S5). Upon receiving the notification, the reference value setting unit 26 starts counting from that point (S6). Once counting has started, the reference value setting unit 26 determines whether the count value has reached the standby time (S7). If it determines that it has not, the reference value setting unit 26 increments the count value by 1 (S8) and then returns to S7. The reference value setting unit 26 repeats S7 and S8 until it determines in S7 that the count value has reached the standby time.

When it is determined in S7 that the count value has reached the standby time, the reference value setting unit 26 instructs the RGB value acquisition unit 22 to acquire a reference value (S9). Upon receiving the instruction, the RGB value acquisition unit 22 sends the RGB values acquired at that time to the memory unit 23 (S10). The memory unit 23 stores the input RGB values as reference values (S11). Through the processing of S1 to S11 up to this point, the reference values of the carrier tape 10 are automatically acquired and stored in the memory unit 23.

As shown in FIG. 9, when the reference value is stored, the determination unit 4 reads the reference value from the storage unit 23 and sets it in the seam detection unit 24 (S12). The seam detection unit 24 compares the RGB value input from the RGB value acquisition unit 22 with the reference value to calculate the degree of mismatch therebetween (S13), and determines whether the degree of mismatch exceeds the seam detection threshold (S14). If the seam detection unit 24 determines in S14 that the degree of mismatch has not been exceeded, it proceeds to S16 to determine whether an operation end signal has been received from the outside, and if it determines that an operation end signal has not been received, it returns to S13.

On the other hand, if the splice detection unit 24 determines in S14 that the splicing tape 15 has been exceeded, it notifies the output unit 27 that it has detected the splicing tape 15 (S15), and the output unit 27 then notifies the outside. Thereafter, the process proceeds to S16 to determine whether an operation end signal has been received from the outside, and if it determines that it has not been received, the process returns to S13. If the determination unit 4 determines in S16 that an operation end signal has been received, it ends the light projection by the light projection unit 2 and the detection of the amount of light received by the light reception unit 3 (S17), and the operation ends.

(8. Main Effects)
According to the above configuration, the seam portion of the carrier tape 10 is detected by detecting the difference (color difference) in color information between the carrier tape 10 and the splicing tape 15. Even if the carrier tape 10 meanders, the carrier tape 10 does not deviate from the irradiation area. This makes it possible to detect the seam portion without any problem even if the carrier tape 10 meanders.

When detecting the splicing tape 15 based on differences in color information in this way, it is preferable to use a splicing tape 15 that is different in color from the carrier tape 10. In other words, it is suitable to use blue, light blue, yellow, and black splicing tapes 15 for a white carrier tape 10. It is suitable to use blue, light blue, and yellow splicing tapes 15 for a black, transparent, and gray carrier tape 10.

However, when using the detection sensor technology of Patent Document 1, the user must visually confirm that the carrier tape 10 is present in the irradiation area and operate a teaching switch to store the reference value of the carrier tape 10. In addition, the user must operate a mode change switch to switch between a teaching mode for storing the reference value and an operation mode.

In contrast, with the above configuration, the leading edge detection unit 25 detects that the leading edge of the carrier tape 10 has reached the irradiation area, and the reference value setting unit 26 sets the RGB values after the waiting time has elapsed since the leading edge was detected as the reference values. This makes it possible to set the reference values automatically without visual inspection. Therefore, there is no need to operate the mode change switch or teaching switch, which must be performed visually, and the reference values can be set automatically, improving the convenience of the color sensor 1.

In addition, the calculation unit (see FIG. 5) calculates the waiting time using the transport speed of the carrier tape 10. The waiting time is a factor that determines the timing for acquiring and setting the reference value from the point in time when the leading edge of the transported object is detected by the leading edge detection unit, and if the waiting time is short, there is a risk that the reference value will be set based on the amount of light received when the transported object does not enter the entire irradiation area. By using the waiting time calculated from the transport speed, it is possible to always set the reference value accurately.

In addition, according to the above configuration, a first threshold value higher than the amount of received light and a second threshold value lower than the amount of received light are set as the path detection threshold value based on the amount of received light detected when the tape path 104 is present in the entire irradiation area. Therefore, even if the color of the carrier tape 10 is a color that reflects more light than the tape path 104, or a color that reflects less light, it is possible to detect the arrival of the tip of the carrier tape 10.

§3 Modifications Although the embodiment of the present invention has been described above in detail, the above description is merely an example of the present invention in every respect. It goes without saying that various improvements and modifications can be made without departing from the scope of the present invention. For example, the following modifications are possible. In the following, the same reference numerals are used for the same components as in the above embodiment, and the description of the same points as in the above embodiment is omitted as appropriate. The following modifications can be combined as appropriate.

(1) In the embodiment described above, the memory unit 23 includes a seam detection threshold table, an aisle detection threshold table, a conveying speed storage unit, and a reference value storage unit. Then, when operation starts, values are read from the memory unit 23, and the aisle detection threshold is set in the leading edge detection unit 25, the conveying speed in the calculation unit 29, and the seam threshold in the seam detection unit 24. However, this configuration is not limited to this, and the seam detection threshold, aisle detection threshold, and conveying speed may be input from the control unit of the master tape feeder 100 at the start of operation.

[Software implementation example]
Each block of the determination unit 4 may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or may be realized by software. In the latter case, the determination unit 4 includes a computer that executes instructions of a program, which is software that realizes each function. This computer includes, for example, one or more processors, and a computer-readable recording medium that stores the program. In the computer, the processor reads the program from the recording medium and executes it, thereby achieving the object of the present invention. The processor may be, for example, a CPU (Central Processing Unit). The recording medium may be a "non-transient tangible medium", such as a ROM (Read Only Memory), a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like. The computer may further include a RAM (Random Access Memory) that expands the program. The program may be supplied to the computer via any transmission medium (such as a communication network or a broadcast wave) that can transmit the program. Note that one aspect of the present invention may also be realized in the form of a data signal embedded in a carrier wave, in which the program is embodied by electronic transmission.

The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. The technical scope of the present invention also includes embodiments obtained by appropriately combining the technical means disclosed in different embodiments.

1 Color sensor 2 Light projecting unit 3 Light receiving unit 4 Determination unit 10 Carrier tape (transported object)
15 Splicing tape (connecting tape)
21 Light projection control unit 22 RGB value acquisition unit (acquisition unit)
23 Memory unit 24 Seam detection unit 25 Tip detection unit 26 Reference value setting unit (setting unit)
29 Calculation unit 100 Tape feeder 104 Tape path (path)

Claims (4)

a light-projecting unit that projects light;
a light receiving unit that detects an amount of reflected light from an irradiation area of the light projected from the light projecting unit;
an acquisition unit that acquires color information of an object present in the illumination area based on the amount of received light;
a seam detection unit that detects a seam of the transported object by comparing the acquired color information with a reference value of the transported object transported through the irradiation area;
a leading edge detection unit that detects that a leading edge of the transported object has reached the illumination area by comparing a detected amount of received light with a passage detection threshold value that is set based on an amount of received light detected when a passage for transporting the transported object is present in the entire illumination area;
a calculation unit that calculates a waiting time from a time when the arrival of the leading end is detected to a time when the reference value is acquired, using a conveying speed of the conveyed object;
a setting unit that, when the waiting time has elapsed from the time when the arrival of the tip is detected, sets the color information acquired at that time as the reference value. The sensor device according to claim 1, wherein the calculation unit calculates the waiting time using the transport speed and the length of the irradiation area in the transport direction. The sensor device according to claim 2, wherein the passage detection threshold is set based on the amount of received light detected when the passage is present throughout the entire illumination area, and a first threshold value higher than the amount of received light and a second threshold value lower than the amount of received light are set. The sensor device according to any one of claims 1 to 3, wherein the transported object is a carrier tape on which multiple components are mounted in a row along the longitudinal direction, and has a joint portion connected in the longitudinal direction by a joining tape.

Images