Device for detecting the life of an image forming process unit, opening of a seal of the unit and attachment of the unit to an image forming apparatus

A device for detecting the life of a process unit which is detachably mounted in an image forming apparatus, the process unit being of the type having a developing device including a developing roller in a casing, the combination comprising:

• sensor means for detecting the density of the toner in said developing device;
• signal detecting means receiving an output from said sensor means and operable to determine whether said output exceeds or is less than a predetermined value during a predetermined time period which starts after said developing roller starts rotating;
• and
• control means connected to said signal detecting means and operable to effect different operating conditions depending on whether said output exceeds or is below said predetermined value, one of said operating conditions being an indication that the life of said process unit has expired and another of said operating conditions being an indication that the life of said process unit is unexpired.

A device for detecting the life of a process unit which is detachably mounted in an image forming apparatus, the process unit being of the type having a developing device and a container with a removeable seal member, the combination comprising:

• sensor means providing an output for detecting the density of the toner in said developing device and for detecting the condition of said seal;
• signal detecting means receiving said output from said sensor means and operable to determine whether said output exceeds or is less than a predetermined value;
• control means connected to said signal detecting means and operable to effect different operating conditions depending on whether said output exceeds or is below said predetermined value, one of said operating conditions being an indication that the life of said process unit has expired and another of said operating conditions being an indication that the life of said process unit is unexpired;
• and
• operable means receiving said output from said sensor means and operable to provide a seal condition output indicative of whether said process unit has been placed in said image forming apparatus with or without the seal having been removed from the process unit.

A device for detecting the life of a process unit which is detachably mounted in an image forming apparatus, the process unit being of the type having a developing device and a container with a seal member which can be opened, the combination comprising:

• sensor means providing an output for detecting the density of the toner in said developing device;
• signal detecting means receiving said output from said sensor means and operable to determine whether said output exceeds or is less than a predetermined value;
• and
• operable means receiving said output from said sensor means and operable to provide a seal condition output indicative of whether said process unit has been placed in said image forming apparatus with or without the seal having been opened.

A device for detecting the life of a process unit which is detachably mounted in an image forming apparatus, the process unit being of the type having a developing device and a cooperable attachment means to effect a cooperable attachment between the image forming apparatus and the process unit, the combination comprising:

• sensor means providing an output for detecting the density of the toner in said developing device and for detecting the condition of said attachment means;
• signal detecting means receiving said output from said sensor means and operable to determine whether said output exceeds or is less than a predetermined value;
• control means connected to said signal detecting means and operable to effect different operating conditions depending on whether said output exceeds or is below said predetermined value, one of said operating conditions being an indication that the life of said process unit has expired and another of said operating conditions being an indication that the life of said process unit is unexpired;
• and
• operable means receiving said output from said sensor means and operable to provide an attachment condition output indicative of whether or not said process unit has been attached to said image forming apparatus by said cooperable attachment means.

A device for detecting the life of a process unit which is detachably mounted in an image forming apparatus, the process unit being of the type having a developing device and a cooperable attachment means to effect a cooperable attachment between the image forming apparatus and the process unit, the combination comprising:

• sensor means providing an output for detecting the density of the toner in said developing device;
• signal detecting means receiving said output from said sensor means and operable to determine whether said output exceeds or is less than a predetermined value;
• and
• operable means receiving said output from said sensor means and operable to provide an attachment condition output indicative of whether or not said process unit has been attached to said image forming apparatus by said cooperable attachment means.