Developing device using two-component type developer having doctor blade resiliently abutted against openings in vessel and an outlet portion in vessel to discharge the developer

A developing device using a two-component developer including a toner component and a magnetic component, comprising:

• vessel means for holding the two-component developer;
• magnetic roller means, rotatably provided within said vessel means, for entraining and bringing the two-component developer to a developing zone for a development of an electrostatic latent image;
• and
• agitator means, provided in said vessel means, for agitating and circulating the two-component developer to cause a triboelectrification between the toner component and the magnetic component and a uniform distribution of the toner component in the magnetic component, said agitator means including at least two screw members arranged in parallel with each other to define passages for circulating the two-component developer, and a partition member, having two end portions, provided between said two screw members and extended therealong, said partition member having a length shorter than that of said two screw members, so that said circulating passages are in communication with each other at the two end portions of said partition member,
• said vessel means having an outlet port formed in a bottom thereof for discharging the two-component developer from said vessel means, said outlet port being positioned at an end zone of said circulating passages through which the two-component developer propelled by one of the screw members is introduced to the other screw member.

A developing device using a two-component developer including a toner component and a magnetic component, comprising:

• vessel means for holding the two-component developer;
• magnetic roller means, rotatably provided within said vessel means, for entraining and bringing the two-component developer to a developing zone for a development of an electrostatic latent image;
• agitator means, provided in said vessel means, for agitating and circulating the two-component developer to cause a triboelectrification between the toner component and the magnetic component and a uniform distribution of the toner component in the magnetic component, said agitator means including at least two screw members arranged in parallel with each other to define a developer circulating passage;
• an outlet port, formed in a bottom of said vessel means, for discharging the two-component developer from said vessel means, the outlet port of said vessel means being positioned at a location along said developer circulating passage;
• and
• slidable shutter means, incorporated into the bottom of said vessel means, for moving between a first position at which said slidable shutter means closes said outlet port and a second position at which said slidable shutter means opens said outlet port, said slidable shutter means including at least two shutter elements spaced from each other and securely connected to and integrated with each other, and opposite side edges of each said shutter element being slidably received in two side grooves which are formed in opposite side wall faces partially defining the outlet port of said vessel means, respectively, so as to form a labyrinth seal therebetween.

A developing device using a two-component developer, comprising:

• a vessel to hold the two-component developer, said vessel including two opposing side walls, each of which has a first opening and a second opening formed therein, said first and second openings arranged to establish a predetermined positional relationship therebetween;
• a magnetic roller rotatably provided within said vessel and supported by inserting end portions of said magnetic roller means into the first openings in the two side walls of said vessel, respectively, to entrain and bring the two-component developer to a developing zone for a development of an electrostatic latent image;
• a doctor blade provided within said vessel, to uniformly regulate an amount of the two-component developer entrained by said magnetic roller, said doctor blade having two end portions movably inserted into the second openings in the two side walls of said vessel, respectively;
• and
• a resilient member to resiliently abut each of the end portions of said doctor blade against an end edge of each of the second openings formed in the corresponding side wall of said vessel, to position said doctor blade at a predetermined and fixed clearance amount from said magnetic roller based on said predetermined positional relationship, for a uniform regulation of an amount of the two-component developer entrained by said magnetic roller.

A developing device using a two-component developer including a toner component and a magnetic component, comprising:

• a vessel to hold the two-component developer;
• a magnetic roller rotatably provided within said vessel, to entrain and bring the two-component developer to a developing zone for a development of an electrostatic latent image;
• and
• an agitator provided in said vessel, to agitate and circulate the two-component developer to cause a triboelectrification between the toner component and the magnetic component and a uniform distribution of the toner component in the magnetic component, said agitator including at least two screw members arranged in parallel with each other to define developer circulating passages, and a partition member, having two end portions, provided between said two screw members and extended therealong, said partition member having a length shorter than that of said two screw members, so that said developer circulating passages are in communication with each other at the two end portions of said partition member,
• said vessel having an outlet port formed in a bottom thereof to discharge the two-component developer from said vessel, said outlet port being positioned at an end zone of said developer circulating passages through which the two-component developer propelled by one of the screw members is introduced to the other screw member.

A developing device using a two-component developer including a toner component and a magnetic component, comprising:

• a vessel to hold the two-component developer;
• a magnetic roller rotatably provided within said vessel, to entrain and bring the two-component developer to a developing zone for a development of an electrostatic latent image;
• an agitator provided in said vessel, to agitate and circulate the two-component developer to cause a triboelectrification between the toner component and the magnetic component and a uniform distribution of the toner component in the magnetic component, said agitator including at least two screw members arranged in parallel with each other to define a developer circulating passage;
• an outlet port formed in a bottom of said vessel, to discharge the two-component developer from said vessel, the outlet port of said vessel being positioned at a location along said developer circulating passage;
• and
• a slidable shutter incorporated into the bottom of said vessel, to move between a first position at which said slidable shutter closes said outlet port and a second position at which said slidable shutter opens said outlet port, said slidable shutter including at least two shutter elements spaced from each other and securely connected to and integrated with each other, and opposite side edges of each said shutter element being slidably received in two side grooves which are formed in opposite side wall faces partially defining the outlet port of said vessel, respectively, so as to form a labyrinth seal therebetween.