System for monitoring material dispensed onto a substrate

A dispensing arrangement for dispensing a material onto a substrate comprising:

• dispensing means responsive to a dispenser control signal for dispensing a material onto a substrate;
• means for producing a dispenser control signal at an output which is coupled to the dispensing means;
• a sensor positioned near the dispensing means to receive radiant energy from a substrate and from material dispensed onto a substrate by the dispensing means, the sensor having an electrical characteristic whose value varies in part in dependence upon the amount of energy, in at least a given energy band, received by the sensor;
• amplifier means electrically connected to the sensor for producing an output signal which varies in dependence upon the value of said electrical characteristic of the sensor, the amplifier means including an amplifier (a) having an input capacitively coupled to the sensor and (b) producing said output signal at an output;
• and
• means, coupled to the means for producing a dispenser control signal, for clamping the input of the amplifier to a particular voltage level when the sensor is receiving radiant energy from a substrate and for unclamping the input of the amplifier before the sensor receives radiant energy from material dispensed onto a substrate.

A system for monitoring energy radiant from a material dispensed onto a substrate comprising:

• a sensor positioned to receive radiant energy from a substrate and from a material dispensed onto the substrate, the sensor having an electrical characteristic whose value varies in part in dependence upon the amount of energy, in at least a given energy band, received by the sensor;
• amplifier means electrically connected to the sensor for producing an output signal which varies in dependence upon the value of said electrical characteristic of the sensor, the amplifier means including an amplifier (a) having an input coupled to the sensor and (b) producing said output signal at an output;
• means, coupled to the sensor and responsive to the value of said electrical characteristic of the sensor when the sensor is receiving radiant energy from the substrate, for coupling to the amplifier input a sensor signal representative of the difference between (a) the value of said electrical characteristic of the sensor when the sensor is receiving radiant energy from material dispensed onto the substrate and (b) the value of said electrical characteristic of the sensor when the sensor is receiving radiant energy from the substrate;
• and
• keying means for coupling a keying signal to the means for coupling when the sensor is receiving radiant energy from the substrate so that the means for coupling is responsive to the value of said electrical characteristic of the sensor when the sensor is receiving radiant energy from the substrate.

A system for monitoring energy radiant from a material dispensed onto a substrate comprising:

• a sensor positioned to receive radiant energy from a substrate and from a material dispensed onto the substrate, the sensor having an electrical characteristic whose value varies in part in dependence upon the amount of energy, in at least a given energy band, received by the sensor;
• means, coupled to the sensor and responsive to the value of said electrical characteristic of the sensor when the sensor is receiving radiant energy from the substrate, for producing a sensor signal representative of the difference between (a) the value of said electrical characteristic of the sensor when the sensor is receiving radiant energy from material dispensed onto the substrate and (b) the value of said electrical characteristic of the sensor when the sensor is receiving radiant energy from the substrate;
• and
• means for clamping the sensor signal to a particular level when the sensor is receiving radiant energy from the substrate and for unclamping the sensor signal before the sensor receives radiant energy from material dispensed onto the substrate.

A system for monitoring energy radiant from a material dispensed onto a substrate comprising:

• sensor means for receiving radiant energy from a substrate and from a material dispensed onto the substrate, the sensor means having an output providing a signal correlated to the amount of energy, in at least a given energy band, received by the sensor means;
• amplifier means, having an input for producing an output signal at an output corresponding to a signal at the input of the amplifier means;
• a capacitor connected between the output of the sensor means and the input of the amplifier means;
• and
• means for clamping the input of the amplifier means to a particular voltage level when the sensor means is receiving radiant energy from the substrate and for unclamping the input of the amplifier before the sensor means receives radiant energy from material dispensed onto the substrate.

A dispensing arrangement for dispensing a material onto a substrate comprising:

• dispensing means responsive to a dispenser control signal for dispensing a material onto a substrate;
• means for producing a dispenser control signal at an output which is coupled to the dispensing means;
• sensor means, positioned near the dispensing means, for receiving radiant energy from a substrate and from material dispensed onto a substrate by the dispensing means, the sensor means having an output providing a signal correlated to the amount of energy, in at least a given energy band, received by the sensor means;
• amplifier means, having an input, for producing an output signal at an output corresponding to a signal at the input of the amplifier means;
• a capacitor connected between the output of the sensor means and the input of the amplifier means;
• and
• means, coupled to the means for producing a dispenser control signal, for clamping the input of the amplifier means to a particular voltage level when the sensor means is receiving radiant energy from a substrate and for unclamping the input of the amplifier means before the sensor means receives radiant energy from material dispensed onto a substrate.

A system for monitoring energy radiant from a material dispensed unto a substrate comprising:

• sensor means for receiving radiant energy from a substrate and from a material dispensed onto the substrate, the sensor means having an output providing a signal correlated to the amount of energy, in at least a given energy band, received by the sensor means;
• amplifier means, having an input, for producing an output signal at an output corresponding to a signal at the input of the amplifier means;
• coupling means, responsive to the value of said electrical characteristic of the sensor when the sensor means is receiving radiant energy from the substrate, for coupling to the input of the amplifier means a sensor signal representative of the difference between (a) the signal provided at said output of the sensor means when the sensor means is receiving radiant energy from material dispensed onto the substrate and (b) the signal provided at said output of the sensor means when the sensor means is receiving radiant energy from the substrate;
• and
• means for clamping the input of the amplifier means to a particular level when the sensor means is receiving radiant energy from the substrate and for unclamping the input of the amplifier before the sensor means receives radiant energy from material dispensed onto the substrate.