Electric power supply system for LED lighting unit

1. An electric power supply system for LED lighting unit that constitutes a work imaging system to take an image of a work as an object to be taken by an imaging device such as a CCD camera and to process the image so as to inspect a flaw formed on a surface of the work or to read a mark such as an alignment mark, and characterized by comprising

an LED lighting unit that has an LED conducting circuit including at least an LED and a resistor for type identification having resistance corresponding to a specification or a characteristics of use of the LED conducting circuit and that irradiates light on the work and an electric power supply unit that has a type identify portion consisting of a resistor measuring circuit that can be connected with the resistor for type identification and a constant current control portion that supplies a control current in an arbitrary range not over the maximum allowable current of the LED conducting circuit set based on the resistance of the resistor for type identification measured by the type identify portion to the LED conducting circuit.

2. The electric power supply system for LED lighting unit described in claim 1 , further comprising a light control signal receive portion that receives a light control signal and a range switch portion that can be switched to at least two states, an ordinary state and a low electric power consumption state and so arranged that the constant current control portion supplies a control current corresponding to a value of a received light control signal to the LED conducting circuit, and

so arranged in case the range switch portion is switched to the ordinary state, a control current having the maximum allowable current is supplied to the LED conducting circuit when a value of the received light control signal is the maximum, meanwhile

in case the range switch portion is switched to the low electric power consumption state, a control current smaller than the maximum allowable current is supplied to the LED conducting circuit even though a value of the received light control signal is the maximum.

3. The electric power supply system for LED lighting unit described in claim 1 , wherein the maximum allowable current can be set in a graded manner based on resistance of the resistor for type identification.

4. An electric power supply system for LED lighting unit characterized by comprising an LED lighting unit that has an LED conducting circuit including at least an LED and a resistor for type identification having resistance corresponding to a specification or a characteristics of use of the LED conducting circuit and

an electric power supply unit that supplies electric power to the LED conducting circuit of the LED lighting unit and that has a type identify portion consisting of a resistor measuring circuit that can be connected with the resistor for type identification and a constant current control portion that supplies a control current in an arbitrary range not over the maximum allowable current of the LED conducting circuit set based on the resistance of the resistor for type identification measured by the type identify portion to the LED conducting circuit.

5. The electric power supply system for LED lighting unit described in claim 4 , further comprising a light control signal receive portion that receives a light control signal and a range switch portion that can be switched to at least two states, an ordinary state and a low electric power consumption state and so arranged that the constant current control portion supplies a control current corresponding to a value of a received light control signal to the LED conducting circuit, and

so arranged in case the range switch portion is switched to the ordinary state, a control current having the maximum allowable current is supplied to the LED conducting circuit when a value of the received light control signal is the maximum, meanwhile

in case the range switch portion is switched to the low electric power consumption state, a control current smaller than the maximum allowable current is supplied to the LED conducting circuit even though a value of the received light control signal is the maximum.

6. The electric power supply system for LED lighting unit described in claim 4 , wherein the maximum allowable current can be set in a graded manner based on resistance of the resistor for type identification.

7. An electric power supply system for LED lighting unit characterized by comprising an LED lighting unit that has an LED conducting circuit including at least an LED and a resistor for type identification having resistance corresponding to a specification or a characteristics of use of the LED conducting circuit and connected with the LED conducting circuit in parallel and

an electric power supply unit consisting of a constant current supply unit that can be connected with the LED conducting circuit in order to supply electric power to the LED conducting circuit of the LED lighting unit and that comprises a type identify portion to measure resistance of the resistor for type identification by impressing a measure voltage of a level that does not affect an operation of the LED conducting circuit to the resistor for type

identification connected with the LED conducting circuit for an extremely short time, a constant current control portion that supplies a control current in an arbitrary range not over the maximum allowable current of the LED conducting circuit set based on the resistance of the resistor for type identification that is connected in parallel that is measured by the type identify portion to the LED conducting circuit after the measure voltage is impressed, and a breaking of wiring identify portion that monitors a condition of electric power supply/a connecting condition between the LED lighting unit and the electric power supply unit and that reboots the type identify portion when the condition of electric power supply/the connecting condition is broken.

8. The electric power supply system for LED lighting unit described in claim 7 , further comprising a light control signal receive portion that receives a light control signal and a range switch portion that can be switched to at least two states, an ordinary state and a low electric power consumption state and so arranged that the constant current control portion supplies a control current corresponding to a value of a received light control signal to the LED conducting circuit, and

so arranged in case the range switch portion is switched to the ordinary state, a control current having the maximum allowable current is supplied to the LED conducting circuit when a value of the received light control signal is the maximum, meanwhile

in case the range switch portion is switched to the low electric power consumption state, a control current smaller than the maximum allowable current is supplied to the LED conducting circuit even though a value of the received light control signal is the maximum.

9. The electric power supply system for LED lighting unit described in claim 7 , wherein the maximum allowable current can be set in a graded manner based on resistance of the resistor for type identification.