JP3868603B2 - Component recognition system for surface mounters - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a component recognition of a surface mounter that uses an optical detection means having an irradiating unit for irradiating light and a light receiving unit, and detects a component suction position based on detection of projection of a component sucked by a suction head. It relates to the device.
[0002]
[Prior art]
Conventionally, a suction head having a nozzle is mounted on a movable head unit, and a small electronic component such as an IC is sucked from a tape feeder or the like of the component supply unit and transferred onto a printed circuit board. A surface mounter that is mounted at a predetermined position on a printed circuit board is generally known.
[0003]
In such a surface mounter, as shown in FIG. 6, an irradiation unit A1 that irradiates light from one side to a component sucked by the nozzle N of the suction head, and an irradiation unit A1 that sandwiches the component. An optical detection means A comprising a light receiving part A2 that receives light at an opposing position is provided in the head unit, and a detection surface orthogonal to the nozzle axis between the irradiation part A1 and the light receiving part A2 of the optical detection means A. There is also known a component recognition device that detects a projection of a suction component located on (a plane through which light radiated from the irradiation unit A1 and reaches the light receiving unit A2) and detects the component suction position based on the projection. Yes.
[0004]
The irradiation unit A1 in the conventional optical detection means A shown in the figure has a point light source B using a light emitting diode (LED) or the like and a lens system such as a cylindrical lens C, and radiates from the light source B. The diffused light thus spread is bent by the lens system so as to become parallel light on the detection surface, and the parallel light beam is irradiated toward the suction component. On the other hand, the light receiving unit A2 is a CCD or the like. The line sensor D is used, and based on the amount of light received by the line sensor D, the projection of the suction component is detected on a fixed detection line.
[0005]
[Problems to be solved by the invention]
In the conventional structure as described above, a light shielding plate is usually provided in the light receiving portion A2, and irradiation light is incident on the line sensor D through a slit formed in the light shielding plate. That is, disturbance light is shielded and only the parallel light emitted from the light source B is received by the line sensor D.
[0006]
However, it is not always sufficient to provide the slit. For example, disturbance light may be scattered at the slit portion and the light may enter the line sensor D, thereby affecting the recognition result of the component. Therefore, from the viewpoint of improving the component recognition accuracy, it is desirable to more reliably block the incidence of such disturbance light.
[0007]
SUMMARY OF THE INVENTION An object of the present invention is to provide a component recognition method and apparatus for a surface mounter that can effectively enhance the recognition accuracy of components by more reliably blocking ambient light.
[0008]
[Means for Solving the Problems]
In order to solve the above-described object, the present invention provides an irradiation unit that emits light from one side to a component sucked by a nozzle of a suction head, and a position facing the irradiation unit across the component. An optical detection means comprising a light receiving portion for receiving light, and the optical detection means detects projection of the component on a certain detection line in the light receiving portion, and based on this, the component suction position by the suction head In the component recognizing device for a surface mounter, the light receiving unit guides only the detection light in a specific direction for component projection irradiated from the irradiation unit onto the detection line while totally reflecting the light. this together with the light other than the detection light provided a prism which transmits without leading to the detection line, further provided with a light blocking member located between said part and the prism in the detection of the projection The optical member is obtained by forming a slit through which light of the specific direction.
[0009]
According to this apparatus, only detection light in a specific direction for component projection reaches the detection line, and other light, that is, disturbance light passes through the prism without reaching the detection line. Therefore, the incidence of disturbance light on the detection line is effectively prevented. In particular, as a result of the provision of a light-shielding member positioned between the component and the prism during projection detection, and a slit through which the light in the specific direction passes through the light-shielding member, disturbance light on the detection line Is more reliably prevented.
[0010]
In this case, a right angle prism having a critical angle of less than 45 ° and a value close to 45 ° is used as the prism, and light in the specific direction is incident perpendicularly to the inclined side of the prism, and is sequentially equilateral. If the prism and the detection line are arranged so as to reach the detection line after being converted by 180 ° by total reflection, the above configuration can be achieved with a simple configuration using the prism of the most basic form. It becomes possible to obtain an effect.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
[0013]
1 and 2 show an example of a surface mounter according to the present invention. As shown in the figure, on a base 1 of a surface mounter (hereinafter abbreviated as a mounter), a printed circuit board transporting conveyor 2 is arranged, and the printed circuit board 3 is transported on the conveyor 2 to be predetermined. Is stopped at the mounting work position. On the front and rear sides of the conveyor 2, there are provided component supply sections 4 each consisting of a plurality of rows of tape feeders 4a and the like.
[0014]
Above the base 1, a component mounting head unit 5 is provided. The head unit 5 has an X-axis direction (the direction of the conveyor 2) and a Y-axis direction (a direction orthogonal to the X-axis on a horizontal plane). ) Can be moved to.
[0015]
That is, the base 1 is provided with a pair of fixed rails 7 extending in the Y-axis direction and a ball screw shaft 8 that is rotationally driven by a Y-axis servo motor 9. A member 11 is disposed, and a nut portion 12 provided on the support member 11 is screwed onto the ball screw shaft 8. The support member 11 is provided with a guide member 13 extending in the X-axis direction and a ball screw shaft 14 driven by an X-axis servo motor 15 so that the head unit 5 can move on the guide member 13. A nut portion (not shown) held by the head unit 5 is screwed onto the ball screw shaft 14. Then, the ball screw shaft 8 is rotated by the operation of the Y-axis servo motor 9 and the support member 11 is moved in the Y-axis direction, and the ball screw shaft 14 is rotated by the operation of the X-axis servo motor 15, thereby the head unit. 5 moves in the X-axis direction with respect to the support member 11. The Y-axis servo motor 9 and the X-axis servo motor 15 are provided with encoders 10 and 16 for detecting drive positions, respectively.
[0016]
The head unit 5 is provided with a suction head 20. The suction head 20 can be moved up and down and rotated with respect to the frame of the head unit 5, and although not shown in detail, a lifting drive means and a R axis servo motor using a Z-axis servo motor 22 as a drive source. It is driven by a rotational drive means having 24 as a drive source. A nozzle 21 for component suction is provided at the lower end of the suction head 20, and at the time of component suction, negative pressure is supplied from a negative pressure supply means (not shown) to the nozzle 21, and the component is attracted by the suction force of the negative pressure. It is adsorbed.
[0017]
Further, a detection unit 30 (optical detection means) for detecting the suction state of the component 29 sucked by each nozzle 21 is provided below the head unit 5.
[0018]
As shown in FIGS. 3 and 4, the detection unit 30 includes irradiation units facing each other across a space where the component 29 sucked by the nozzle 21 of the suction head 20 is at a predetermined recognition height. 30a and a light receiving portion 30b.
[0019]
The irradiation unit 30a irradiates the component 29 adsorbed by the nozzle 21 with light, and includes a point light source 31 made of a light emitting diode and a cylindrical lens 32, and detects light from the light source 31. It is comprised so that it may become parallel light on a surface.
[0020]
On the other hand, the light receiving unit 30b includes a line sensor 34 (detection line) in which light receiving elements such as CCD sensors are arranged in a line and a prism 33. The light is reflected by the prism 33 while reflecting light from the irradiation unit 30a. It is configured to enter the sensor 34.
[0021]
The prism 33 is a so-called right angle prism which is the most basic form, and in the present application, a prism having a critical angle of less than 45 ° and a value as close to 45 ° as possible is used. As shown in FIG. 4, in the prism 33, the inclined side 33a is orthogonal to the light from the light source 31, that is, the parallel light L (light in a specific direction) on the detection surface, and the equal sides 33b and 33c are positioned vertically. As described in detail later, the parallel light L is converted in the direction of 180 °. The line sensor 34 is arranged so that its light receiving surface faces the inclined side 33a of the prism 33, and receives the parallel light L that has been converted by the prism 33 by 180 °.
[0022]
In the mounting machine including the component recognition device as described above, after the component is sucked from the component supply unit by the suction head 20 of the head unit 5, the component 30 is irradiated with the irradiation unit 30a of the detection unit 30 and receives light. In a state where the height position of the suction component 29 is adjusted such that the component 29 is positioned on the detection surface between the irradiation unit 30b and the irradiation unit 30a, the component 29 is irradiated with the parallel light L and received by the light receiving unit 30b. The projection of the part 29 is detected by checking the quantity. Based on the detection of the projection, the component suction position is checked by a conventionally known method. For example, the projection width and the projection center position are detected while the component 29 is rotated, and the component suction is detected based on the data. Misalignment is required. Then, the component mounting position is corrected according to the shift of the component suction position.
[0023]
When component recognition processing is performed using the detection unit 30 as described above, according to the apparatus of this embodiment, the parallel light L from the irradiation unit 30a is guided to the line sensor 34 while being reflected by the prism 33 as described above. Therefore, the incidence of disturbance light on the line sensor 34 is effectively prevented, thereby improving the component recognition accuracy.
[0024]
This action will be specifically described with reference to FIG. 5. The parallel light L emitted from the irradiation unit 30a passes through the inclined side 33a of the prism 33 and first enters the upper equal side 33b. At this time, since the incident angle of the parallel light L with respect to the equilateral side 33b is 45 ° and is larger than the critical angle of the prism 33, the parallel light L is totally reflected by the equilateral side 33b and redirected downward by 90 °. Then, after 90 ° direction conversion while being totally reflected at the lower equal side 33c, the light is emitted from the inclined side 33a and reaches the line sensor 34.
[0025]
On the other hand, light that is not parallel to the parallel light L, for example, light La that has an angle α upward with respect to the parallel light L (that is, light that is incident on the inclined side 33a obliquely from above) is slightly transmitted along the transmission of the inclined side 33a. The light is refracted and enters the upper equal side 33b. In this case, since the incident angle of the light La with respect to the equilateral side 33b becomes larger than 45 °, the light La is totally reflected by the equilateral side 33b and enters the lower equilateral side 33c. At this time, since the incident angle of the light La with respect to the equal side 33b is equal to the reflection angle, the incident angle of the light La with respect to the equal side 33c is smaller than 45 °. Therefore, the light La incident on the equilateral 33c at an angle smaller than the critical angle is transmitted through the equilateral 33c. When the incident angle is smaller than 45 ° and larger than the critical angle, the light La is totally reflected at the equilateral side 33c. However, as described above, the critical angle is less than 45 ° and extremely high at 45 °. Since the values are close to each other, most of the light La from obliquely above passes through the equal side 33c and hardly reaches the line sensor 34.
[0026]
On the other hand, also in the case of light Lb having an angle β downward with respect to the parallel light L (that is, light incident on the inclined side 33a from an obliquely lower side), the light is refracted slightly along with the transmission of the inclined side 33a and is transmitted to the upper equal side 33b. Incident. However, in this case, since the incident angle of the light Lb with respect to the equilateral side 33b is smaller than 45 ° as opposed to the case of the light La, most of the light Lb is transmitted through the equilateral side 33b.
[0027]
For this reason, the so-called disturbance light other than the parallel light L such as the light La and Lb does not reach the line sensor 34, thereby effectively preventing the disturbance light from entering the line sensor 34. Therefore, compared with a conventional apparatus of this type in which parallel light is received by a line sensor through a slit formed in the light shielding plate, the influence of disturbance light is extremely low, and the accuracy of projection detection is improved.
[0028]
By the way, the detection unit 30 is an example of a component recognition apparatus according to the present invention, and the specific configuration thereof can be appropriately changed without departing from the gist of the present invention.
[0029]
For example, in addition to the configuration of the detection unit 30, a light shielding plate 35 (light shielding member) is provided as indicated by a broken line in FIG. 4 so that the parallel light L enters the prism 33 through a slit 36 formed in the light shielding plate 35. It may be. In this way, most of the disturbing light can be shielded by the light shielding plate 35, so that it is possible to more effectively prevent the disturbing light from entering the line sensor 34.
[0030]
In the detection unit 30, a right angle prism having a critical angle of less than 45 ° and a value as close as possible to 45 ° is used as the prism, but the prism shape and critical angle are limited to this. Instead, it may be selected as appropriate so as to effectively prevent the reception of disturbance light. However, since the right-angle prism is the most basic form of the prism, there is an advantage that the above-described effects can be obtained with a simple and inexpensive configuration.
[0031]
【The invention's effect】
As described above, according to the present invention, in an apparatus in which light is irradiated onto a component from the irradiation unit of the optical detection unit and the projection is detected on the detection line of the light receiving unit, a prism is provided in the light receiving unit. Since the prism guides only the detection light in a specific direction for component projection onto the detection line while totally reflecting it, it transmits light other than the detection light without reaching the detection line. It is possible to effectively prevent the disturbance light from being received and to improve the accuracy of component recognition. In particular, when a projection is detected, a light-shielding member is provided between the component and the prism, and a slit that allows light in the specific direction to pass is formed in the light-shielding member. Is more reliably prevented.
[0032]
In particular, as the prism, a right-angle prism having a critical angle of less than 45 ° and a value close to 45 ° is used, and light in the specific direction is incident perpendicularly to the inclined side of the prism, and all the same sides are sequentially arranged. If the prism and the detection line are arranged so as to reach the detection line after being changed in the direction of 180 ° by reflection, the above operation can be achieved with a simple configuration using the prism in the most basic form. An effect can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic plan view showing an example of a mounting machine equipped with an apparatus of the present invention.
FIG. 2 is a schematic front view of the same.
FIG. 3 is a schematic plan view showing a configuration of a detection unit.
FIG. 4 is a schematic front view showing a configuration of a detection unit.
FIG. 5 is a schematic diagram of a prism for explaining the operation of a detection unit.
FIG. 6 is a schematic plan view showing a conventional apparatus.
[Explanation of symbols]
5 Head unit 20 Suction head 21 Nozzle 29 Component 30 Detection unit 30a Irradiation unit 30b Light reception unit 31 Light source 32 Cylindrical lens 33 Prism 33a Inclined side 33b Equal side 34 Line sensor L Parallel light

Claims (2)

Optical detection comprising an irradiating unit that irradiates light from one side to a component adsorbed by the nozzle of the adsorption head and a light receiving unit that receives light at a position facing the irradiating unit across the component. A component of a surface mounter that detects the projection of the component on a fixed detection line in the light receiving unit by the optical detection unit and obtains the component suction position by the suction head based on the projection In the recognizing device, the light receiving unit guides only the detection light in a specific direction for projecting the component irradiated from the irradiation unit onto the detection line while totally reflecting the light, while the light other than the detection light is directed to the detection line. a prism which transmits without leading provided, further, Sri passing the light of a specific direction on the light blocking member provided with a light shielding member positioned between the component and the prism in the detection of the projection Component recognition device of a surface mounting machine, characterized in that to form the door.   As the prism, a right angle prism having a critical angle of less than 45 ° and a value close to 45 ° is used, and the light in the specific direction is incident perpendicularly to the inclined side of the prism and is sequentially totally reflected on the same side. 2. The component recognition apparatus for a surface mounter according to claim 1, wherein the prism and the detection line are arranged so as to reach the detection line after the direction is changed by 180 [deg.].

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