Image recognition apparatus and method for surface discrimination using reflected light
View Patent ↗In an image recognition method, the image of a cream solder 9 printed on a rectangular electrode 16 having a solder leveler formed is picked up and recognized to identify the cream solder 9 . An illuminating unit having white light source parts 35 W arranged in the radial oblique directions of 45° is used to apply white color illumination lights from a light applying direction in which an angle of θ1 formed by the light applying direction and a horizontal plane in a vertical plane is 45° or smaller and from a light applying direction in which an angle of θ3 formed by the light applying direction and the boundary of the electrode 16 in a horizontal plane is 75° or smaller. Thus, regularly reflected lights from a solder leveler forming surface 16 a with a glossiness are not received by an upper camera to identify a solder surface 9 a and the solder leveler forming surface 16 a with good accuracy.
1. An image recognition apparatus in which an image obtained by picking up an image of an object to be recognized that includes a background surface, a first surface with a glossiness and a second surface with a glossiness lower than that of the first surface in a recognition surface, the first surface being partitioned by a rectangular boundary and the second surface being provided on the first surface in the background surface, is subjected to a recognition process to discriminate the first surface from the second surface in the background surface, said image recognition apparatus comprising:
an illuminating part for applying illumination light to the object to be recognized upon picking up the image;
a camera for receiving the reflected light of the illumination light from an upper part to pick up the color image of the object to be recognized; and
a recognizing process part for recognizing image data obtained by the camera and discriminating the first surface from the second surface based on a luminance difference between the first surface and the second surface in said image,
wherein the illuminating part includes a first illuminating unit for applying white illumination light to the object to be recognized from a first light applying direction in which regularly reflected light from the first surface is not received by the camera and a second illuminating unit for applying colored illumination light to the object to be recognized from a second light applying direction in which the reflected light from the first surface is received by the camera,
wherein an angle, that occurs in a vertical plane, and that is formed by the first light applying direction with both of the first surface and the background surface, is not greater than 45 degrees, and an angle, that occurs in a horizontal plane, and that is formed by the first light applying direction and the boundary, is not greater than 75 degrees, and
wherein an angle, that occurs in a vertical plane, and that is formed by the second light applying direction with both of the first surface and the background surface, is not greater than 45 degrees.
2. An image recognition apparatus according to claim 1 , wherein the object to be recognized is a board for mounting electronic parts after a solder printing, the background surface shows the surface of the board, the first surface shows an electrode for connecting the electronic parts provided on the board and having a solder leveler formed on its surface and the second surface shows a cream solder printed on the electrode.
3. An image recognition apparatus according to claim 2 , wherein, the image is picked up after the cream solder is printed on the electrode and before an electronic part is mounted on the electrode.
4. An image recognition method in which an image obtained by picking up an image of an object to be recognized that includes a background surface, a first surface with a glossiness and a second surface with a glossiness lower than that of the first surface in a recognition surface, the first surface being partitioned by a rectangular boundary and the second surface being provided on the first surface in the background surface, is subjected to a recognition process to discriminate the first surface from the second surface in the background surface, said image recognition method comprising the steps of:
irradiating the object to be recognized with white illumination light by a first illuminating unit from a first light applying direction in which regularly reflected light from the first surface is not received by a camera when the object to be recognized is irradiated with the illumination light by an illuminating part and the reflected light of the illumination light is received from an upper part to pick up the image of the object to be recognized, wherein an angle, that occurs in a vertical plane, and that is formed by the first light applying direction with both of the first surface and the background surface, is not greater than 45 degrees, and an angle, that occurs in a horizontal plane, and that is formed by the first light applying direction and the boundary, is not greater than 75 degrees; and
irradiating the object to be recognized with colored illumination light by a second illumination unit from a second light applying direction in which the reflected light from the first surface is received by the camera, wherein an angle, that occurs in a vertical plane, and that is formed by the second light applying direction with both of the first surface and the background surface, is not greater than 45 degrees; and
discriminating the first surface from the second surface based on a luminance difference between the first surface and the second surface in said image.
5. An image recognition method according to claim 4 , wherein the background surface shows a board for mounting electronic parts, the first surface shows an electrode for connecting the electronic parts provided on the board and having a solder leveler formed on its surface and the second surface shows a cream solder printed on the electrode.
6. An image recognition method according to claim 5 , wherein the image is picked up after the cream solder is printed on the electrode and before an electronic part is mounted on the electrode.