Device and method for picking up image of component, and component mounting apparatus

An image pickup camera is arranged, so that a plurality of components are adapted to be sequentially imaged by corresponding image pickup device with a timing whereby light for imaging is prevented from affecting the other image pickup operation while the components are let to pass above the image pickup camera. The hold posture of each of the plurality of components can be imaged separately without decreasing the cycle time.

BACKGROUND OF THE INVENTION

The present invention relates to, for example, an image pickup method for electronic components to be mounted on a printed circuit board, a component image pickup apparatus that carries out the image pickup method, and a component mounting apparatus with the component image pickup apparatus.

Improving reliability on a working process and shortening a cycle time are greatly required in order to improve productivity in a mounting process for electronic components in these years. Conventionally, in a mounting apparatus for mounting electronic components such as chip components and IC components onto a circuit board, a suction posture of the electronic component at a nozzle that holds the electronic component and mounts the same to the circuit board is picked up with the use of an image pickup device such as a CCD camera. A suction state, a suction position and the like are recognized on the basis of the picked up-image, and positions of the nozzle and a head having the nozzle are corrected in accordance with recognized information so that the electronic component can be correctly mounted at a mounting position on the circuit board. Components are mounted in this manner (see, for instance, publication of unexamined Japanese patent application No. 60-1900).

For further improving the productivity recently, an idea is conceived that a plurality of nozzles for sucking electronic components are arranged, thereby transferring a plurality of electronic components to a mounting area at a time to mount the same. In picking up images of the components as above in this configuration, while it is necessary to pick up image of the suction state of each of electronic components sucked by the plurality of nozzles, each of the electronic components should be picked up through illumination under an illumination condition conforming to the each electronic component because the electronic components sucked by the nozzles are different in types.

As a method for picking up an image, it is possible to pick up image of the electronic components one by one with the use of one camera and one illumination device, which unfavorably takes a long time. For example, given that 5 nozzles are arranged in an array by a pitch of 10.75 mm to require 10 ms to move by each pitch, and 33 ms is necessary to transfer the obtained image, a total of 205 ms is necessitated.

On the other hand, if image pickup is to be carried out at a time by using a plurality of cameras and preparing a plurality of illumination devices, in the case, e.g., where a nozzle interval is short as in an arrangement by the pitch of 10.75 mm, light from each illumination devices interfere with each other, thereby obstructing normal imaging.

The present invention is developed to solve the problem, and has for its object to provide a component image pickup apparatus for picking up images of hold postures of a plurality of components separately without decreasing a cycle time, a component image pickup method carried out by the component image pickup apparatus, and a component mounting apparatus with the component image pickup apparatus.

SUMMARY OF THE INVENTION

In order to accomplish the above objective, the present invention is configured as described below.

Specifically, according to a first aspect of the present invention, there is provided a component image pickup apparatus including:

a component holding head which has a plurality of component holding members and for moving in a movement direction; and

an image pickup camera for picking up an image of each of components held by the component holding members,

the image pickup camera comprising:

a plurality of image pickup devices arranged corresponding to a plurality of paths respectively where the component holding members pass by the movement in the movement direction, for picking up the images of the components held by the component holding members;

single illuminator arranged for the plurality of image pickup devices for applying light at an image pickup operation by each image pickup device; and

an image pickup controller for controlling the image pickup operation to each image pickup device and the illuminator in accordance with an image pickup condition related to each image pickup device and set for every component and an illumination condition related to the illuminator.

The component image pickup apparatus of the first aspect may be designed so that the device further comprises a recognizer connected to the image pickup camera for supplying the image pickup condition and the illumination condition to the image pickup controller before the component holding head reaches above the image pickup camera, controlling the image pickup operation to each image pickup device and the illuminator, and receiving image information from each image pickup device after the imaging.

The component image pickup apparatus of the first aspect may be designed so that the image pickup devices are disposed at respective setting positions where the image pickup devices pick up the images of components one by one with a time difference in accordance with the movement of the component holding members in the movement direction.

The component image pickup apparatus of the first aspect may be designed so that the setting positions of a first image pickup device and a second image pickup device for imaging next to the first image pickup device are disposed at positions separated by at least a distance which is obtained by multiplying a moving velocity in the movement direction of the component holding head and an exposure time at the first image pickup device.

The component image pickup apparatus of the first aspect may be designed so that the component holding members are arranged at equal intervals along a circumference, while the movement direction is a direction parallel to a diametrical direction of the circumference and passing through two of the component holding members arranged at the equal intervals.

Further, according to a second aspect of the present invention, there is provided a component image pickup method comprising:

supplying an image pickup condition and an illumination condition necessary for imaging each of components and set for every component to an image pickup camera while a component holding head with a plurality of component holding members moves to above the image pickup camera which has a plurality of image pickup devices for imaging respective components held by the component holding members, and single illuminator;

letting the component holding head pass above the image pickup camera along a movement direction without stopping the head after the supplying; and

sequentially imaging the components by the respective image pickup devices during the passing with a timing whereby effects of light for imaging of the illuminator are avoided.

Further, according to a third aspect of the present invention, there is provided a component mounting apparatus comprising:

a component image pickup apparatus;

a component holding head having a plurality of component holding members respectively for holding electronic components and mounting the held electronic components to a circuit board;

a drive unit for moving the component holding head in a movement direction; and

a circuit board holding unit for holding the circuit board,

the component image pickup apparatus including:

an image pickup camera for picking up an image of each of components held by the component holding members,

the image pickup camera having:

a plurality of image pickup devices arranged corresponding to a plurality of paths respectively where the component holding members pass by the movement in the movement direction, for picking up the images of the components held by the component holding members;

single illuminator arranged for the plurality of image pickup devices for applying light at an image pickup operation by each image pickup device; and

an image pickup controller for controlling the image pickup operation to each image pickup device and the illuminator in accordance with an image pickup condition related to each image pickup device and set for every component and an illumination condition related to the illuminator.

According to the component image pickup apparatus of the first aspect, the component image pickup method of the second aspect and the component mounting apparatus of the third aspect of the present invention, there is included the image pickup camera, and a plurality of components are adapted to be sequentially imaged by respective image pickup devices at the timing whereby the light for imaging is prevented from affecting the other image pickup operation while the plurality of components are let to pass above the image pickup camera. The hold posture of the plurality of components can be imaged separately without decreasing the cycle time.

Moreover, since the image pickup condition and the illumination condition necessary for the image pickup operation for all of the components are preliminarily supplied to the image pickup camera before imaging is started, the need of transferring the image pickup condition and the illumination condition at every time of imaging each component is eliminated and the communication delay is prevented. The components to be imaged can be moved at a higher speed and can be imaged as well.

The image pickup camera can be equipped with the recognizer, and according to this arrangement, an operation load of the image pickup camera can be reduced.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A component image pickup apparatus, a component image pickup method and a component mounting apparatus as embodiments of the present invention will be described hereinafter with reference to drawings. The component image pickup method is a method carried out by the component image pickup apparatus, and the component mounting apparatus includes the component image pickup apparatus. Like parts are designated by like reference numerals throughout the drawings.

As indicated inFIGS. 1 and 2, the component image pickup apparatus has an image pickup camera110which is equipped with a plurality of image pickup devices111, single illuminator112, and an image pickup controller115with a sequencer113and a storage114, as fundamental constituent parts. The component image pickup apparatus can include a recognizer150to be connected to the image pickup camera110. The image pickup camera110has an interface116formed as a connecting part to the recognizer150.

This component image pickup apparatus100is a device for picking up each of images of components251held by each suction nozzle211when a component holding head210moves in a movement direction250, as shown inFIG. 2. The component holding head210has six suction nozzles211, namely, suction nozzles211-1to211-6as an example functioning as a component holding member, which are arranged at equal intervals by every 60° of a central angle on a circumference.

According to the present embodiment as above, the component holding head210has the six suction nozzles211arranged at equal intervals on the circumference. Therefore, three paths252-1to252-3(generically denoted as the path252in some cases) each passing two suction nozzles211can be formed in a diametrical direction of the circumference and in a direction parallel to the movement direction250as shown inFIG. 3. For example, suction nozzles211-1and211-6pass the path252-1, suction nozzles211-2and211-5pass the path252-2, and suction nozzles211-3and211-4pass the path252-3. The image pickup device111are disposed correspondingly to the paths252-1to252-3respectively. More specifically, image pickup device111-1,111-2and111-3are disposed below the path252-1, below the path252-2and below the path252-3respectively. Moreover, the image pickup device111-1and111-2are arranged on the same axis255along an orthogonal direction253orthogonal to the movement direction250. The image pickup device111-1and111-2are arranged by a shift or displacement of a distance254in the movement direction250from the image pickup device111-3.

The reason that the image pickup device111-1and the image pickup device111-2can be arranged on the same axis255is that, as is clear fromFIG. 3, the suction nozzles211-1and211-2are disposed at displaced positions in the movement direction250because of the arrangement in the embodiment in which the suction nozzles211are arranged at six points respectively via the equal interval on the circumference, thereby allowing the image pickup device111-1and111-2to pick up images at different timings. In contrast to this, the suction nozzle211-1and the suction nozzle211-3are disposed at the same position in the movement direction250, and therefore the image pickup device111-3is displaced by the distance254to the image pickup device111-1and111-2based on the reason to be described below.

The reason for the above arrangement with the displacement is that the image pickup device111-1to111-3need to pick up images one by one so that light for picking up the image from one of the image pickup devices111in an image pickup operation does not affect other image pickup operations of remaining pickup devices111.

In the case, e.g., where the image pickup device111-1carries out the image pickup operation and the image pickup device111-3is to carry out the image pickup operation next, the above-referred distance254between the image pickup device111-1and the image pickup device111-3can be a value obtained by multiplying a moving velocity in the movement direction250of the component holding head210and an exposure time at the image pickup device111-1. By arranging with the displacement of at least the above distance254, two image pickup devices111which are to carry out the image pickup operation continuously, each of the exposure at the two image pickup devices111is prevented from overlapping.

When the suction nozzles211and the image pickup devices111are arranged as described hereinabove, the image pickup devices111-1to111-3can pick up the images of the components251at mutually different timings without overlapping the exposure respectively. In other words, as shown inFIG. 4, in accordance with the move of the component holding head210in the movement direction250without stopping, the image of the component251held by the suction nozzle211-2is first picked up by the image pickup device111-2as indicated byFIG. 4A, the image of the component251held by the suction nozzle211-1is picked up next by the image pickup device111-1as indicated byFIG. 4B, and then the image of the component251held by the suction nozzle211-3is picked up by the image pickup device111-3as indicated byFIG. 4C.

Although the image pickup devices111are arranged correspondingly to the paths252where the plurality of nozzles211can pass in common as described here in the embodiment from a viewpoint of reducing the number of image pickup devices111as much as possible, if it is not necessary to take reducing the number of image pickup devices, or the like into account, each image pickup device111can be arranged correspondingly to the path for each suction nozzle211along the movement direction250.

Also from the viewpoint of reducing the number of image pickup devices, six suction nozzles211are aligned on the circumference as illustrated in the embodiment. However, the present invention is not limited to the embodiment. The number of suction nozzles211is not limited. Moreover, an arrangement direction of the suction nozzles211is not limited to on the circumference and the suction nozzles can be, for instance, arranged in an array along an arrangement direction of holding members.

Single illuminator112is installed for the image pickup devices111-1to111-3as indicated inFIG. 2, which is a device for providing illumination for picking up the image at the image pickup operation of each image pickup device111. In the present embodiment, the illuminator112has LEDs112aas a light source fitted in three, namely, upper, middle and lower stages along an up-down direction256orthogonal to the movement direction250and to the orthogonal direction253.

The image pickup controller115is a device for making each image pickup device111and the illuminator112carry out the image pickup operation according to an image pickup condition for each image pickup device111set for every component251to be imaged, and an illumination condition for the illuminator112.

The storage114included in the image pickup controller115is a part for storing a parameter data160as represented inFIG. 5that is sent from the recognizer150. The parameter data160corresponds to the above image pickup condition and illumination condition in the embodiment. These image pickup condition and illumination condition are set correspondingly to each sequence of picking up each of components251. The image pickup condition is information for designating a large visual field imaging or a small visual field imaging to the image pickup devices111, while the illumination condition is a condition for designating a luminance to the illuminator112. Since the illuminator112has LEDs112aarranged in three stages as described above according to the embodiment, the illumination condition is information for indicating which of the three stages of the LEDs112ais (are) to emit light. At least one of the three stages is adapted to emit light.

The sequencer113included in the image pickup controller115reads out the parameter data160from the storage114and sends the image pickup condition and the illumination condition for each sequence to the image pickup devices111and the illuminator112. Operations of the image pickup controller115will be detailed by the following description of the image pickup operation.

The recognizer150sends the parameter data160to the image pickup camera110as above, and moreover generates a trigger signal for starting picking up image by the image pickup device111and the illuminator112and sends the trigger signal to the image pickup device111and the illuminator112. Furthermore, after picking up image, the recognizer150receives a picked up image information from the image pickup camera110and carries out image processing to analyze a hold posture of the component251held by the suction nozzle211.

The component image pickup apparatus100constituted as above can be installed, for example, in an electronic component mounting apparatus200as shown inFIG. 8. In addition to the component image pickup apparatus100, the electronic component mounting apparatus200has the component holding head210, a drive unit230for moving the component holding head210in the movement direction250and the orthogonal direction253, and a circuit board holding unit220for holding a circuit board70to which the electronic components251held by the suction nozzles211are to be mounted. In addition, the electronic component mounting apparatus200can include a component supply unit240for supplying electronic components251, a transfer unit250for transferring the circuit board70, and a controller280for the electronic component mounting apparatus200.

Operations in the above-constructed component image pickup apparatus100, that is, a component image pickup method will be depicted below by adopting an example of a component mounting operation carried out by the above component mounting apparatus200. The description will be focused to only the image pickup operation supposed that components251are already held at suction nozzles211. The image pickup operation is primarily controlled and carried out by the image pickup controller115as described earlier.

To the image pickup controller150is supplied a present position of the component holding head210, i.e., present position information of each of suction nozzles211-1to211-6on the basis of a signal sent out by the drive unit230. Meanwhile, a setting position of each of image pickup devices111-1to111-3is preliminarily detected. Therefore, the recognizer150can detect which of the suction nozzles211has been arranged above the image pickup device111. Also the controller280has, for example, NC data or the like mounting related information necessary for mounting components supplied thereto. Conforming to a control by the controller280, the component holding head210holds a determined component251by each of determined suction nozzles211in accordance with a mounting order. Since the mounting related information is also sent from the controller280to the recognizer150, which of the components251is held by which of the suction nozzles211, in other words, a relation between each suction nozzle211and the electronic component251held by the same is already detected at the recognizer150alike.

Because of being conformed to the mounting related information, components251are not always held by every suction nozzle211. There are some cases in which one or a plurality of suction nozzles211do not hold components251.

As shown inFIG. 7, after suction nozzles211hold electronic components251, the recognizer150sends the parameter data160corresponding to all electronic components251sucked in this time to the image pickup controller115of the image pickup camera110while the component holding head210moves to the image pickup camera110. The storage114of the image pickup camera110stores the parameter data160. The parameter data160includes also sequence data related to an order of imaging.

Referring further toFIG. 6, after the parameter data160is transferred to the image pickup camera110and before the first image pickup operation is started, the sequencer113reads out the image pickup condition and the illumination condition related to the first imaging (SEQ1) from the storage114, sends the image pickup condition to the image pickup device111which is to carry out the first imaging, and sends the illumination condition to the illuminator112. The image pickup device111for the first imaging switches an imaging visual field to large or small in accordance with the image pickup condition.

As described above, since the recognizer150has obtained the correspondence between the image pickup devices111and the suction nozzles211and has grasped the position information of each image pickup device111, the sequencer113knows the imaging order. One that carries out the first imaging is the image pickup device111-2in the example as shown inFIG. 4A.

When the electronic component251sucked by the suction nozzle211-2enters the visual field of the image pickup device111-2as the component holding head210moves in the movement direction250, the sequencer113instructs the image pickup device111-2and the illuminator112to pick up the image in accordance with the trigger signal generated by the recognizer150. The illuminator112emits light by a luminance conforming to the illumination condition and the image pickup device111-2exposes the electronic component with the light.

After the image pickup is finished, the sequencer113reads out the image pickup condition and the illumination condition of a SEQ2related to a second imaging from the storage114, sends the image pickup condition to the image pickup device111which is to carry out the second imaging, i.e., the image pickup device111-1in the example as indicated inFIG. 4Band sends the illumination condition to the illuminator112. The image pickup device111-1switches the visual field to large or small in accordance with the image pickup condition. When the electronic component251sucked by the suction nozzle211-1enters the visual field of the image pickup device111-1, the sequencer113instructs the image pickup device111-1and the illuminator112to pick up the image according to the trigger signal generated by the recognizer150. The illuminator112emits light by a luminance in conformity with the illumination condition and the image pickup device111-1exposes the electronic component with the light.

As is made clear with reference toFIGS. 3 and 4, through repetition of the above-described operation afterwards, the component251held by the suction nozzle211-3, the component251held by the suction nozzle211-6, the component251held by the suction nozzle211-4, and the component251held by the suction nozzle211-5are imaged by the image pickup device111-3at the third imaging, by the image pickup device111-1at the fourth imaging, by the image pickup device111-3at the fifth imaging, and by the image pickup device111-2at the last imaging respectively and continuously, namely, while the component holding head210is moved at a constant velocity in the movement direction250without being stopped.

Each image pickup device111sends information on the image obtained at the time to the recognizer150after finishing the image pickup operation before starting the next image pickup operation.

According to the component image pickup apparatus100of the present embodiment, the plurality of image pickup devices111are adapted to pick up images one by one by shifting image pickup timing from each other, and moreover, the shift of the image pickup timing is made an amount for avoiding effects of the illumination light for the image pickup operation carried out immediately before. Because of the arrangement, all of the electronic components251can be imaged by one simple scan above the image pickup camera110in the movement direction250. The hold posture of a plurality of components can be imaged separately without decreasing a cycle time.

The parameter data160having the image pickup condition and the illumination condition related to the sequence of the image pickup operation is preliminarily transferred to the image pickup camera110before the sequence of the image pickup operation is started. Therefore, the need of setting the image pickup condition and the illumination condition between the recognizer150, and each image pickup device111and the illuminator112is eliminated when the image pickup operation is carried out by each image pickup device111. A communication delay between the recognizer150, and the image pickup devices111and the illuminator112is hence prevented, enabling moving the component holding head210at a higher velocity in the movement direction250as well as enabling the image pickup operation.

In the above embodiment, the image pickup devices111are operated to image one by one. This is to avoid the effect of the light for imaging onto the other image pickup operation in consequence of the short distance of electronic components251to be imaged as is discussed as the problem inherent in the conventional art. The technical concept of the present invention is to shift the image pickup timing to avoid the above effect for image pickup device present in a range where the light for imaging affects the other image pickup operation. Therefore, if components to be imaged are separated by a degree whereby the effect is avoided, it is possible to pick up the images concurrently at a plurality of image pickup devices. However, since the image pickup condition varies for every component as described before, it is impossible to unconditionally specify a range where the effect is avoided. The image pickup timing should be shifted at least in imaging adjacent components.

Although the electronic component is exemplified as the component to be imaged in the present embodiment, the component to be imaged is not limited to this.