JPH08235925A - Lighting system and electronic part assembling and inspecting device using the system - Google Patents

Abstract

PURPOSE: To precisely pick up an image without depending on the surface conditions or others of an object. CONSTITUTION: A lighting system has cylindrical outside and inside light guides 9, 12 made of transparent resin material and plural light sources 13, 14 to inject illuminated light into the light guides 9, 12. Illuminated light from the light sources 13, 14 are transferred through the light guides 9, 12 while being totally reflected and outputted from the inclined planes 9a, 12a at the ends to the center.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device and a technique effectively applied to an assembly / inspection device for electronic parts and the like using the same.

[0002]

2. Description of the Related Art For example, when mounting and assembling electronic components such as ICs, chip resistors or capacitors on an electronic circuit formed on a printed circuit board, an electronic component mounting apparatus called a so-called chip mounter is used to automatically perform work. It is customary to do so.

In this case, the work is executed while imaging or recognizing the electronic parts and the electronic circuit of the printed circuit board on which the electronic parts are mounted by using the imaging device of the CCD camera.

An illumination device is used for better imaging and recognizing electronic components and circuits for this work.

Such an illuminating device is also used for the same purpose in an inspection device for electronic parts and the like.

By the way, as an example of such an illuminating device, it is considered to illuminate a printed circuit board to be illuminated with a single illuminating means or a light source.

[0007]

However, when illuminating with a single illuminating means, the surface condition of the printed circuit board to be targeted is very diverse, so that a single illuminating means can cover all the substrates. Is quite difficult, and there are cases where the reflection of the light source (direct reflected light) is harmful and vice versa, where mark identification is difficult unless the contrast of linear reflection is used.

Also, in the case of a diffused light source, there are a case where the direct reflected light is effective and a case where only the diffused reflected light is used (the reflection of the light source is not considered) is effective.

There is no standard in this respect for the fiducial mark that is generally used for this kind of identification mark, and it is currently required to adapt to various states.

Therefore, the inventor of the present invention has found that it is preferable that the light source has a large area and has no unevenness in brightness, and that it is desirable that the irradiation angle and brightness of the object can be arbitrarily set during the mounting work. I found it.

An object of the present invention is to provide an illuminating device capable of more accurately capturing or recognizing an object even if the conditions such as the surface condition of the object are various.

Another object of the present invention is to provide an apparatus for assembling / inspecting an electronic component or the like using an illuminating device capable of accurately capturing or recognizing an electronic component or an electronic circuit which is an example of an object. .

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0014]

Of the inventions disclosed in the present application, a representative one will be briefly described below.
It is as follows.

That is, the illuminating device of the present invention uses a plurality of cylindrical light guides, each of which is made of a transparent material, receives light from the base ends of these light guides, and causes a total reflection phenomenon in the light guides. The advancing light is output from the tip to irradiate the target site with an angle. The tip of the outer light guide projects further than the tip of the inner light guide, and each tip of each light guide is formed as a tapered inclined surface from the outer peripheral side toward the inner peripheral side,
The light transmitted from a plurality of light sources through each light guide is output toward the center of each light guide.

The light guide may have a cylindrical structure which is easy to manufacture and low in cost, and can be made of, for example, an acrylic resin material.

The plurality of light sources are light emitting diodes, for example, and can be turned on / off by switching for each light guide according to the object to be illuminated, and the luminous intensity of the light emitting diodes can be variably adjusted.

[0018]

According to the above-mentioned illumination device of the present invention, the light from the plurality of light sources is transmitted while being reflected in each light guide by the total reflection phenomenon, and is output from the inclined surface at the tip to the illuminated portion.

At this time, the luminous intensity or brightness of the light source can be variably adjusted according to the state of the object to be illuminated, and the light source can be turned on and off for each light guide.
The position of the light guide can be changed with respect to the illuminated object.

Therefore, it is possible to always illuminate under optimum conditions according to the state of the illuminated portion.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic explanatory view of an assembly / inspection device for electronic parts incorporating a lighting device according to the present invention, and FIG. 2 is a schematic plan view showing an example of arrangement of light sources in the lighting device according to the present invention.
(a) and (b) are respectively a plan view and a longitudinal sectional view of the outer light guide used in the present invention, and FIGS. 4 (a) and (b) are a plan view and a longitudinal sectional view of the inner light guide used in the present invention, respectively. FIG. 5, FIG. 5 is a view for explaining an example of the light output state in the inner and outer light guides, FIG. 6 (a), (b), (c),
(d), (e) is a figure explaining some examples of the entrance, transmission, and output of the light in an inner light guide.

In the present embodiment, the illuminating device 1 has an elongated hole 3 provided in the bracket 2 and a set screw 4 inserted through the elongated hole 3 so that the illuminating device 1 can be axially or higher than the electronic component assembling / inspecting device 5. It is attached so that the position in the vertical direction can be adjusted.

As an example of the electronic component assembling / inspecting apparatus 5, for example, an electronic component mounting apparatus called a so-called chip mounter or an electronic component inspecting apparatus can be considered, but other apparatus may be used, and in this embodiment, the electronic component mounting apparatus. Is selected.

A printed circuit board 6 as an example of an object to be illuminated is located below the lighting device 1, and an electronic circuit (not shown) for mounting electronic components is mounted on the printed circuit board 6. It is formed of printed wiring and the like.

On the other hand, on the upper side of the lighting device 1, a camera 7 as an image pickup device which constitutes a part of the electronic component assembling / inspecting device 5 is provided, and an electronic circuit on the printed circuit board 6 or the like should be mounted. An electronic component or the like is imaged and recognized by image processing.

The illumination device 1 includes an outer light guide 9 supported by an outer support ring 8 attached to the bracket 2.
And an inner light guide 12 supported by an inner support ring 11 which is also attached to the bracket 2, and a plurality of (light guides arranged above the light guides 9 and 12 with a slight gap therebetween. In the embodiment, as shown in FIG. 2, light sources 13 and 14 each consisting of 16 light emitting diodes (LEDs) are provided in the circumferential direction.

Both of the light guides 9 and 12 have a transparent cylindrical structure made of a resin material such as acrylic resin (see FIGS. 3 and 4). Therefore, the light source 1
The light that has entered the light guides 9 and 12 from 3 and 14 is transmitted through the inside by the so-called total reflection phenomenon and output from the tip. Then, the camera 7 can image the illuminated portion through the inner cylindrical space of the inner light guide 12.

The tip of the outer light guide 9 is the same as the tip of the inner light guide 12 or protrudes ahead of the latter.

The tips of the light guides 9 and 12 are
The inclined surfaces 9a and 12 are tapered from the outer peripheral side toward the inner peripheral side.
It has a structure in which a and a are formed. As a result, the light output from the inclined surfaces 9a and 12a at the tips of the light guides 9 and 12 is directed toward the center.

In the present embodiment, the outer light guide 9
The inclined surface 9a has an inclination angle of about 63.4 ± 0.5 degrees with respect to the tip end surface (the surface perpendicular to the axis).

On the other hand, the inclined surface 12a of the inner light guide 12 of this embodiment forms an inclination angle of about 26.6 ± 0.1 degrees with respect to the tip end surface (the surface perpendicular to the axis).

Therefore, in this embodiment, in addition to the respective lengths of the outer light guide 9 and the inner light guide 12, the inclination angles of the inclined surfaces 9a and 12a are different from each other, and the printed circuit board 6 which is an illumination object. By variably adjusting the position with respect to the long hole 3 and the set screw 4, the light output from each of the light guides 9 and 12 is applied to the illuminated portion at different irradiation angles.

Further, each of the light sources 13 and 14 is connected to a luminous intensity adjusting device 15 or 16 (for example, an adjusting volume) so that the luminous intensity or brightness of the emitted light can be arbitrarily adjusted according to the state of the illuminated portion. Has been done.

Further, each of the light sources 13 and 14 is also connected to a switching device 17 or 18 (for example, a switching switch) for switching on and off depending on the state of the illuminated portion.

Next, the operation of this embodiment will be described.

First, the height of the illumination device 1 with respect to the object to be illuminated, that is, the printed circuit board 6 is adjusted and set to a desired height by the elongated hole 3 and the set screw 4.

When the light sources 13 and 14 are turned on and turned on, the illuminations from the light sources 13 and 14 are incident from the proximal end faces of the outer and inner light guides 9 and 12, respectively, and are transmitted in the axial direction to be transmitted at the tip ends. As shown in FIG. 5, the inclined surfaces 9a and 12a are output toward the center and are irradiated onto the illuminated portion of the printed circuit board 6.

At this time, a part of the illumination light incident on each of the light guides 9 and 12 directly passes through each of the light guides 9 and 12 as it is, or a part of each of the light guides 9 and 12 is directly transmitted.
The light propagates while being reflected by the inner or outer surface of 12 due to the total reflection phenomenon, and is output from the inclined surfaces 9a and 12a.
The transmission mode of the illumination light in each of the light guides 9 and 12 at this time is shown in FIGS. 6 (a) to 6 (e) by taking the inner light guide 12 as an example.

That is, FIG. 6A shows the inner light guide 1
2 shows an example of illumination light that passes directly in the direction of the axis.
(c) shows an example of the illumination light which is totally reflected once on the outer side surface and the inner side surface, and (d) and (e) are totally reflected twice once on the outer side surface and the inner side surface, respectively. The example of illumination light is shown. In any of the examples, the inclined surface 12a at the tip is used.
The illumination light output from the inside is output to the air with a refraction angle due to the difference in the refractive index between the resin material of the inner light guide 12 and the air.

The illumination light output from each of the light guides 9 and 12 is directed toward the center and is applied to an illuminated portion such as an electronic circuit on the printed circuit board 6.

At this time, since the illumination lights from the respective light guides 9 and 12 are emitted at different irradiation angles, even under the situation where shadows or halation are generated due to the shape or color of the illumination target, for example, 2 By using one (or more) of each of the light guides 9, 12, the respective illuminating lights advantageously act on each other to prevent the generation of shadows and halation.

As a result, in this embodiment, the camera 7 can accurately capture the image of the illumination target. The imaging result is image-processed by the image processing device 19, the object is accurately recognized, and the control device 20 automatically controls the assembly / inspection device 5 based on the recognition result.

Further, depending on the state (shape, color, etc.) of the illumination target, the luminous intensity or brightness of the illumination light from the light sources 13, 14 is optimally variably adjusted by adjusting the luminous intensity adjusting devices 15, 16. A clear image can be captured accurately.

Further, depending on the state of the illumination object, there may be a case where the illumination light from only one of the light sources 13 and 14 is more accurate than the illumination light from both the light sources 13 and 14. Therefore, in that case, more accurate imaging can be performed by performing illumination while controlling the light sources 13 and 14 to be turned on and off by the switching devices 17 and 18.

Prior to the automatic mounting work, various teaching conditions such as the light sources 13 and 14 of the lighting device 1 are taught and stored in the computer according to the conditions such as the shape of the illuminated object and the surface condition. As a result, it is possible to accurately execute the automatic mounting of electronic components while the camera 7 takes images in the optimum state.

Although the invention made by the present inventor has been specifically described based on the embodiments, the invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, the number of light sources, the number of light guides, the inclination angle of the tip thereof, and the material and shape of the light guides can be changed.

In the above description, the case where the invention made by the present inventor is mainly applied to the technology of assembling and inspecting electronic parts, which is the field of use of the invention, is not limited to this and, for example, other illuminations are used. It can also be applied to illumination of objects.

[0049]

Advantageous effects obtained by typical ones of the inventions disclosed in the present application will be briefly described.
It is as follows.

(1). By using a plurality of transparent cylindrical light guides and a plurality of light sources, the irradiation area can be increased and the uneven brightness can be obtained without being affected by the surface condition or shape of the illumination target. It is possible to suppress and always perform accurate imaging under optimum conditions.

(2) By appropriately selecting the length of the light guide and the inclination angle of the tip, it is possible to always perform the optimum imaging under the optimum conditions.

(3) Optimum imaging according to the condition of the illuminated object by variably adjusting the light intensity of the light source for each light guide or by turning on or off both or one of them. You can

(4) Since the light guide has a cylindrical structure, it is easier and cheaper to manufacture than other shapes, and it is convenient to use a normal transparent pipe or the like.

(5). By making the light guide with a resin material such as an acrylic resin, it is possible to manufacture a light guide of desired quality at low cost.

(6). By allowing the position of the light guide with respect to the object to be illuminated to be variably adjusted in the axial direction, optimum image pickup can always be performed.

(7) By making the angles of the inclined surfaces at the tips of the respective light guides different from each other, the irradiation area or irradiation angle of the illumination light on the object can be increased or the balance can be improved.

(8) According to the above (1) to (7), it is possible to perform accurate image pickup, image processing based on the image pickup, and accurate mounting and inspection of electronic components by recognition.

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram of an electronic component assembling / inspecting apparatus incorporating a lighting device according to the present invention.

FIG. 2 is a schematic plan view showing an arrangement example of light sources in the lighting apparatus of the present invention.

3 (a) and 3 (b) are respectively a plan view and a vertical sectional view of an outer light guide used in the present invention.

4A and 4B are a plan view and a vertical sectional view of an inner light guide used in the present invention, respectively.

FIG. 5 is a diagram illustrating an example of a light output state in the inner and outer light guides.

6 (a), (b), (c), (d), and (e) are diagrams for explaining some examples of incident, transmission, and output of light in the inner light guide.

[Explanation of symbols]

 1 Lighting Device 2 Bracket 3 Long Hole 4 Set Screw 5 Electronic Component Assembling / Inspecting Device 6 Printed Circuit Board 7 Camera 8 Outer Support Ring 9 Outer Light Guide 9a Inclined Surface 11 Inner Support Ring 12 Inner Light Guide 12a Inclined Surface 13, 14 Light Source 15, 16 Luminance adjusting device 17, 18 Switching device 19 Image processing device 20 Control device

Claims (9)

[Claims] 1. An inner light guide having a tubular structure made of a transparent material, and a tube made of a transparent material, which is located outside the inner light guide and has a tip protruding from the tip of the inner light guide. And a plurality of light sources that are installed on the proximal end sides of the inner and outer light guides and that allow light to enter the respective light guides through their proximal end surfaces, and Each tip of the outer light guide forms a tapered inclined surface from the outer peripheral side toward the inner peripheral side, and the light transmitted from the light source through the inside of each light guide is directed toward the center of each light guide. The lighting device is characterized by outputting to. 2. The lighting device according to claim 1, wherein the inner and outer light guides have a cylindrical structure. 3. The lighting device according to claim 1, wherein the light source is a light emitting diode, and the luminous intensity of each of the light emitting diodes is variable. 4. The lighting device according to claim 1, 2 or 3, wherein the light source can be switched on and off for each of the inner light guide and the outer light guide depending on an object to be illuminated. 5. The lighting device according to claim 1, 2, 3 or 4, wherein the inner and outer light guides are made of a resin material such as acrylic resin. 6. The illumination device according to claim 1, 2, 3, 4 or 5, wherein the positions of the inner and outer light guides with respect to the illumination target can be variably adjusted in the axial direction. 7. The lighting device according to claim 1, 2, 3, 4, 5 or 6, wherein the angles of the inclined surfaces of the tips of the inner and outer light guides are different from each other. 8. An inner light guide having a cylindrical structure made of a transparent material, and a tube made of a transparent material, which is located outside the inner light guide and has a tip protruding from the tip of the inner light guide. An outer light guide having a structure, a plurality of light sources installed on the base end sides of the inner and outer light guides, respectively, and allowing light to enter the respective light guides through the base end surfaces, and installed above the light sources. And a camera for recognizing an illumination target through the inner space of the inner light guide, each tip of the inner and outer light guides has a tapered inclined surface from the outer peripheral side toward the inner peripheral side, and Assembly and inspection of electronic parts, etc., characterized in that the light transmitted from the light source through each of the light guides is output toward the center of each of the light guides. Apparatus. 9. The apparatus for assembling / inspecting electronic components according to claim 8, wherein the illumination target is a printed circuit board for mounting electronic components, and the camera is provided in the electronic component mounting device. Assembling / inspecting device for electronic parts.