Inspection apparatus and inspection method

1. An inspection apparatus for inspecting a target object based on content of a fluorescent component included in the target object, the inspection apparatus comprising:

conveying means for conveying the target object along a conveyance path;

a light-emitting device for emitting light toward the target object conveyed by the conveying means;

a light-detecting device for detecting fluorescence emitted from the target object when irradiated with the light;

a fluorescent member disposed on the conveyance path for generating fluorescence in response to light emitted from the light-emitting device: and

controlling means for, before the target object conveyed by the conveying means arrives at an inspection area of the conveyance path, receiving an output signal from the light-detecting device to detect quantity of the fluorescence generated from the fluorescent member, and for controlling quantity of the light from the light-emitting device based on quantity of the fluorescence generated by the fluorescent member.

2. The inspection apparatus according to claim 1 , wherein the fluorescent member is a fluorescence glass.

3. The inspection apparatus according to claim 1 , further comprising:

a light-detecting portion for outputting a signal depending on quantity of the fluorescence detected by the light-detecting device;

light source control means for controlling quantity of light emitted from the light-emitting device and for changing, in an analog manner, to a pre-determined quantity of light selected by the light source control means for controlling the quantity of the light emitted;

arithmetic means for calculating changing fluorescence quantity; and

decision means for deciding type of the target object based on the changing fluorescence quantity.

4. The inspection apparatus according to claim 3 , wherein the arithmetic means calculates the changing fluorescence quantity from changing quantity of illumination by the light-emitting device by second order differentiating output data from the light-detecting portion.

5. The inspection apparatus according to claim 3 , wherein the decision means decides type of the target object based on a comparison between a pre-determined quantity and the changing fluorescence quantity.

6. An inspection method for inspecting a target object based on content of a fluorescent component included in the target object, the inspection method comprising:

detecting a start signal;

calibrating quantity of light emitted from a light-emitting device by outputting an initial control signal to the light-emitting device,

detecting fluorescence with a light-detecting device while an illuminating member is illuminated by the light emitted by light-emitting device,

deciding an illumination quantity for the light-emitting device by comparing a pre-determined fluorescence and the fluorescence detected until difference between the pre-determined fluorescence and the fluorescence detected becomes zero, and

outputting the illumination quantity as a corrected control signal;

deciding type of the target object based on fluorescence emitted from the target object illuminated by the light emitted by the light-emitting device; and

continuing deciding the type of the target object until a stop signal is detected.

7. The inspection method according to claim 6 , wherein deciding the type of the target object includes:

changing the control signal, based on the corrected control signal, in an analog manner;

calculating a second order differential of changing output from the light-detecting device; and

determining the type of the target object by comparing the second order differential and a pre-determined threshold value.