Patent Description:
As a component mounting machine of this type, there is a component mounting machine, in which a mark imaging camera that images a board mark of a circuit board, on which a component is mounted, images an identification target, such as a character and a mark, on an upper surface of the component supplied by a component supply device, such as a tape feeder, from above, and the image is processed to identify the identification target on the component upper surface, as described in Patent Literature <NUM> (<CIT>). In this case, as an illumination light source for imaging the identification target on the component upper surface, a ring-shaped illumination light source provided in the mark imaging camera is used.

However, since an illumination angle (the optical axis angle of illumination light) with respect to an identification target, such as a character, on the component upper surface, is approximately <NUM>° and an illumination angle suitable for identifying the identification target, such as a character, on the component upper surface, is larger than <NUM>° to <NUM>° in this configuration, it is difficult to identify the identification target, such as a character, on the component upper surface in some cases. In particular, in a case where the identification target, such as a character, on the component upper surface, is engraved by a laser, when the illumination angle is large, there is almost no brightness difference between the identification target and the component upper surface in the vicinity thereof, and the identification target, such as a character, cannot be identified at all.

Thus, as described in Patent Literature <NUM> (<CIT>), there is a technique in which the number of illumination units of a mark imaging camera is increased to be on both sides in an X-direction, character identifying illumination light sources are arranged on both outer sides of a general illumination light source used in illuminating a board mark, and in a case of identifying a character on a component upper surface, by illuminating the character on the component upper surface with the character identifying illumination light sources positioned on both outer sides of the general illumination light source, an illumination angle with respect to the character on the component upper surface is made small and the character on the component upper surface is imaged and identified.

<CIT> relates to placing support pins on a support base for supporting printed wiring boards. Positions for placing the support pins may be indicated by irradiating the surface with a collimated light beam. A camera is mounted next to the light source and can be used to observe the board and the collimated light beam on the surface.

However, since the character identifying illumination light sources are arranged on both outer sides of the general illumination light source used in lighting the board mark in the configuration of Patent Literature <NUM>, the illumination units attached on a lower side of the mark imaging camera are configured to greatly overhang on both outer sides of the camera. In this case, since the mark imaging camera is attached to a mounting head and both are integrally moved during a component pickup and mounting operation, there is a possibility that the illumination units of the mark imaging camera, which moves integrally with the mounting head during the component pickup and mounting operation, interfere with an object existing in the vicinity thereof or a mounted component on a circuit board and thereby damage the object or the mounted component.

The invention is defined by the features of claim <NUM>.

Hereinafter, one embodiment disclosed in the present specification will be described. First, an overall configuration of component mounting machine <NUM> will be described briefly with reference to <FIG> and <FIG>.

Component supply device <NUM>, such as a tray feeder and a tape feeder for supplying component <NUM>, is set in component mounting machine <NUM> in a replaceable manner. Inside component mounting machine <NUM>, head moving device <NUM> that moves mounting head <NUM> in a horizontal direction (X- and Y-directions) and an up-down direction (Z-direction) and conveyor <NUM> that loads/unloads a circuit board (not shown) are provided. One or multiple suction nozzles (not shown) for picking up component <NUM> supplied by component supply device <NUM> and mounting component <NUM> on the circuit board are held by mounting head <NUM> in a replaceable manner. Between component supply device <NUM> and conveyor <NUM>, component imaging camera <NUM> that images component <NUM>, which is picked up by the suction nozzle of mounting head <NUM>, from below is provided to face upward.

As shown in <FIG>, mark imaging camera <NUM> that images a board mark of a circuit board from above is attached downward to a side surface portion of mounting head <NUM>, and mounting head <NUM> and mark imaging camera <NUM> are integrally moved in the X-, Y-, and Z-directions by head moving device <NUM>. Electric component holding frame <NUM> that holds an electric component, such as a control board and cables of mounting head <NUM>, is attached to mounting head <NUM> while protruding to the side of mounting head <NUM>. Illumination light source <NUM> composed of a light emitting element, such as an LED, is attached to a lower portion of electric component holding frame <NUM>. Illumination light source <NUM> is attached such that the amount by which illumination light source <NUM> protrudes from electric component holding frame <NUM> is as small as possible (more preferably, attached such that illumination light source <NUM> does not protrude from electric component holding frame <NUM>), in order to set an attachment angle (angle of the optical axis) such that a character, a symbol, and a mark (hereinafter, referred to as an "identification target"), which is attached to an upper surface of component <NUM> supplied by component supply device <NUM>, is illuminated from obliquely above, and to avoid illumination light source <NUM> interfering with an object existing on the periphery thereof or a mounted component on the circuit board during the movement of mounting head <NUM>.

In this case, when a distance between mark imaging camera <NUM> and illumination light source <NUM> in the horizontal direction is excessively small, the illumination angle (angle of the optical axis) of illumination light source <NUM> with respect to the identification target on the upper surface of component <NUM> positioned below mark imaging camera <NUM> is excessively large, so that the identification target is unlikely to be identified. In consideration of this point, in the present embodiment, the distance between mark imaging camera <NUM> and illumination light source <NUM> in the horizontal direction is made as large as possible by attaching illumination light source <NUM> to an end portion of the lower portion of electric component holding frame <NUM>, which is on an opposite side to the position of mark imaging camera <NUM>, so that the illumination angle of illumination light source <NUM> with respect to the identification target on the upper surface of component <NUM> positioned below mark imaging camera <NUM> is made small.

Further, in the present embodiment, in consideration of the fact that the height of the upper surface of component <NUM> on a tray differs depending on a component type in a case where component supply device <NUM> is a tray feeder, height sensor <NUM> that measures the height of the upper surface of component <NUM> is attached downward to mounting head <NUM>. As height sensor <NUM>, for example, a non-contact height sensor, such as a laser type, an ultrasonic type, and an LED type, need only be used.

Control device <NUM> that controls an operation of each function of component mounting machine <NUM>, which is described above, is composed of one or multiple computers (CPUs) and peripheral circuits thereof, and also functions as an image processing device that processes an image captured by mark imaging camera <NUM> or component imaging camera <NUM> to identify the identification target. When identifying the identification target on the upper surface of component <NUM> supplied by component supply device <NUM>, control device <NUM> controls an operation of head moving device <NUM> such that mark imaging camera <NUM> is moved to a position above component <NUM> and mounting head <NUM> is moved in the up-down direction (Z-direction) until the height of illumination light source <NUM> from the upper surface of component <NUM> reaches a predetermined height with the height of component <NUM>, which is measured by height sensor <NUM>, as reference (that is, until the illumination angle of illumination light source <NUM> with respect to the identification target on the upper surface of component <NUM> reaches a predetermined angle). Accordingly, the identification target on the upper surface of component <NUM> is imaged by mark imaging camera <NUM> and is identified through image processing in a state where the illumination angle of illumination light source <NUM> with respect to the identification target on the upper surface of component <NUM> is adjusted such that the illumination angle of illumination light source <NUM> becomes an illumination angle suitable for identifying the identification target on the upper surface of component <NUM>, that is, for example, falls within a range of <NUM>° to <NUM>° (more preferably, <NUM>° to <NUM>°).

At this time, in a case where the identification target on the upper surface of component <NUM> cannot be identified, control device <NUM> may cause head moving device <NUM> to change the height of illumination light source <NUM> by a predetermined amount so that the illumination angle of illumination light source <NUM> with respect to the identification target on the upper surface of component <NUM> is slightly changed, and perform image processing as mark imaging camera <NUM> images the identification target on the upper surface of component <NUM> again.

Further, an illumination light amount adjusting section (not shown) that adjusts an illumination light amount (brightness) of illumination light source <NUM> is provided, and in a case where the identification target on the upper surface of component <NUM> cannot be identified, the illumination light amount adjusting section may change the illumination light amount (brightness) of illumination light source <NUM> with respect to the identification target on the upper surface of component <NUM> and image processing may be performed as mark imaging camera <NUM> images the identification target on the upper surface of component <NUM> again.

In the present embodiment described above, a configuration where illumination light source <NUM> is provided on electric component holding frame <NUM> is adopted in view of the fact that electric component holding frame <NUM> that holds electrical components, such as a control board and cables of mounting head <NUM>, is provided on mounting head <NUM> while protruding to the side of mounting head <NUM>. Accordingly, illumination light source <NUM> can be composed of a light emitting element, such as an LED, so as to be small in size, and the distance between illumination light source <NUM> and mark imaging camera <NUM> in the horizontal direction can be secured while avoiding an increase in the size of a structure moving integrally with mounting head <NUM> (a problem of interference between a peripheral object and a mounted component on a circuit board) by attaching illumination light source <NUM> to electric component holding frame <NUM> protruding to the side of mounting head <NUM>. Accordingly, without an increase in the size of the structure moving integrally with mounting head <NUM>, the illumination angle of illumination light source <NUM> with respect to the identification target on the upper surface of component <NUM> positioned below mark imaging camera <NUM> can be made as small as an illumination angle suitable for identifying the identification target by arranging illumination light source <NUM> at a position separated from mark imaging camera <NUM> in the horizontal direction, and the identification target on the upper surface of component <NUM> can be identified.

Although mounting head <NUM> is moved in the horizontal direction (X- and Y-directions) and the up-down direction (Z-direction) by head moving device <NUM> in the present embodiment, a component mounting machine that picks up and mounts component <NUM> by causing head moving device <NUM> to move mounting head <NUM> only in the horizontal direction (X- and Y-directions) and causing the suction nozzle to move in the up-down direction (Z-direction) may be applied and realized.

Claim 1:
A component mounting machine (<NUM>) comprising:
an illumination light source (<NUM>) configured to illuminate an identification target, wherein the identification target which is a character, a symbol, or a mark is attached to an upper surface of a component supplied by a component supply device, from obliquely above;
a camera configured to image the identification target on the upper surface of the component, which is illuminated by the illumination light source (<NUM>) from obliquely above; an image processing device (<NUM>) configured to process an image captured by the camera to identify the identification target;
a mounting head (<NUM>) configured to pick up the component to mount the component on a circuit board;
a head moving device (<NUM>) configured to move the mounting head (<NUM>); and
an electric component holding frame (<NUM>), being provided to move integrally with the mounting head, which is configured to hold a control board or cables of the mounting head, while the electric component holding frame (<NUM>) protruding to a side of the mounting head, wherein the illumination light source (<NUM>) is attached to a lower portion of the electric component holding frame (<NUM>),
the camera is a mark imaging camera (<NUM>) configured to move integrally with the mounting head (<NUM>) and to image a board mark of the circuit board, and
the mark imaging camera (<NUM>) is attached downward to a side surface portion of the mounting head (<NUM>);
wherein
the illumination light source (<NUM>) is attached to an end portion of the lower portion of the electric component holding frame (<NUM>), which is on an opposite side to a position of the mark imaging camera (<NUM>), thereby securing a distance between the illumination light source (<NUM>) and the mark imaging camera (<NUM>) in the horizontal direction.