Image forming apparatus and toner cartridge

An image forming apparatus comprising:

• an image holding member;
• a charging unit configured to charge a surface of the image holding member;
• an electrostatic image forming unit configured to form an electrostatic image on the charged surface of the image holding member;
• a developing unit that includes an electrostatic image developer,
• wherein the developing unit is configured to develop the electrostatic image formed on the surface of the image holding member with the electrostatic image developer to form a toner image;
• a transfer unit configured to transfer the toner image onto a surface of a recording medium;
• a fixing unit configured to fix the transferred toner image on the surface of the recording medium;
• a replenishment toner container that includes a replenishment toner that is to be supplied into the developing unit,
• wherein the replenishment toner container is configured to discharge the replenishment toner by rotation of the replenishment toner container;
• a replenishment toner container mounting unit configured to hold the replenishment toner container,
• wherein the replenishment toner container mounting unit is configured to rotate the replenishment toner container;
• and
• a toner supply pass that connects the replenishment toner container mounting unit to the developing unit,
• wherein the toner supply pass is configured to supply the replenishment toner into the developing unit,
• wherein the replenishment toner comprises:
• toner particles;
• and
• silica particles having a number average particle size of 110 nm to 130 nm, a large-diameter-side number particle size distribution index (upper GSDp) of less than 1.080, and an average circularity of 0.94 to 0.98, wherein 80 number % or more of the silica particles have a circularity of 0.92 or more,
• wherein the replenishment toner container includes:
• a toner discharge port formed in an end face of the replenishment toner container in a direction of a longer axis of the replenishment toner container;
• a toner accommodating portion;
• and
• a continuous protrusion formed in an inner surface of the toner accommodating portion so as to extend toward the toner discharge port in a helical pattern, and
• wherein the protrusion has an average width 150 to 2,500 times a volume average particle size of the toner and an average height 150 to 2,500 times the volume average particle size of the toner.

A toner cartridge detachably attachable to an image forming apparatus, the toner cartridge comprising:

• a replenishment toner including:
• toner particles, and
• silica particles having a number average particle size of 110 nm to 130 nm, a large-diameter-side number particle size distribution index (upper GSDp) of less than 1.080, and an average circularity of 0.94 to 0.98, wherein 80 number % or more of the silica particles have a circularity of 0.92 or more,
• wherein the toner cartridge is configured to discharge the replenishment toner by rotation of the toner cartridge,
• wherein the toner cartridge includes:
• a toner discharge port formed in an end face of the toner cartridge in a direction of a longer axis of the toner cartridge;
• a toner accommodating portion;
• and
• a continuous protrusion formed in an inner surface of the toner accommodating portion so as to extend toward the toner discharge port in a helical pattern, and
• wherein the protrusion has an average width 150 to 2,500 times a volume average particle size of the toner particles and an average height 150 to 2,500 times the volume average particle size of the toner particles.

An image forming apparatus comprising:

• a developing device comprising developer and a developer roller,
• wherein the developing device is configured to develop an electrostatic image with the developer to form a toner image;
• and
• a container including a replenishment toner to be supplied to the developing device,
• wherein the replenishment toner comprises:
• toner particles;
• and
• silica particles having a number average particle size of 110 nm to 130 nm, a large-diameter-side number particle size distribution index (upper GSDp) of less than 1.080, and an average circularity of 0.94 to 0.98, wherein 80 number % or more of the silica particles have a circularity of 0.92 or more,
• wherein the replenishment toner container includes:
• a toner discharge port formed in an end face of the replenishment toner container in a direction of a longer axis of the replenishment toner container;
• a toner accommodating portion;
• and
• a continuous protrusion formed in an inner surface of the toner accommodating portion so as to extend toward the toner discharge port in a helical pattern, and
• wherein the protrusion has an average width 150 to 2,500 times a volume average particle size of the toner and an average height 150 to 2,500 times the volume average particle size of the toner.