An image forming apparatus, including: a photoconductor; a developing device; a developer storage; a supplier configured to supply developer; an optical sensor; and a controller configured to execute: a developing process of developing an electrostatic latent image on the photoconductor; a usage-amount obtaining process of obtaining a usage amount of the developer; a supplying process of supplying the developer to the developing device every time when the obtained usage amount becomes equal to or greater than a first threshold; and a detecting process of detecting, by the optical sensor, an amount of the developer in the developing device every time when the obtained usage amount becomes equal to or greater than a second threshold larger than the first threshold, and wherein the controller is configured to execute the detecting process in a period different from a period in which the developing process is being executed.

A developing device includes a housing to accommodate toner, a rotation member installed in the housing, a lens including an optical surface oriented in an axial direction of the rotation member, and a wiper installed in the rotation member and configured to repeatedly wipe the optical surface while the rotation member rotates and supported by the rotation member so as to be movable in the axial direction.

An image forming apparatus, including: a photoconductor; a developing device; a developer storage; a supplier configured to supply developer; an optical sensor; and a controller configured to execute: a developing process of developing an electrostatic latent image on the photoconductor; a usage-amount obtaining process of obtaining a usage amount of the developer; a supplying process of supplying the developer to the developing device every time when the obtained usage amount becomes equal to or greater than a first threshold; and a detecting process of detecting, by the optical sensor, an amount of the developer in the developing device every time when the obtained usage amount becomes equal to or greater than a second threshold larger than the first threshold, and wherein the controller is configured to execute the detecting process in a period different from a period in which the developing process is being executed.

An image forming apparatus includes an image forming portion including a developer storage portion, a fixing apparatus, a detection portion configured to output a detection signal in accordance with a developer amount in the developer storage portion, and a control portion configured to control a target temperature of the fixing apparatus. The control portion is configured to set the target temperature at a first temperature if the developer amount is a first amount, set the target temperature at a second temperature lower than the first temperature if the developer amount is a second amount smaller than the first amount, and set the target temperature at a third temperature higher than the second temperature if the developer storage portion is supplied with the developer such that the developer amount is increased from the second amount to the first amount.

An image forming apparatus, to which a cartridge including a developer accommodating portion for accommodating a developer is detachably mountable, includes an image bearing member, an exposure unit configured to expose the image bearing member to light to form an electrostatic latent image on the image bearing member, a light receiving sensor provided in the cartridge and configured to receive the light emitted from the exposure unit, and a controller configured to detect vibration of the cartridge from a light reception value of the light received by the light receiving sensor. In a case in which the cartridge is removed from the image forming apparatus, the light receiving sensor is removed from the image forming apparatus together with the cartridge.

An image forming apparatus, including: a photoconductor; a developing device; a developer storage; a supplier configured to supply developer; an optical sensor; and a controller configured to execute: a developing process of developing an electrostatic latent image on the photoconductor; a usage-amount obtaining process of obtaining a usage amount of the developer; a supplying process of supplying the developer to the developing device every time when the obtained usage amount becomes equal to or greater than a first threshold; and a detecting process of detecting, by the optical sensor, an amount of the developer in the developing device every time when the obtained usage amount becomes equal to or greater than a second threshold larger than the first threshold, and wherein the controller is configured to execute the detecting process in a period different from a period in which the developing process is being executed.

An electrophotographic image forming apparatus includes a cartridge for forming a visible toner image. The cartridge includes a development chamber having a toner inlet through which toner is supplied into the development chamber, a development roller provided in the development chamber, and a supply roller provided in the development chamber that supplies toner to the development roller. The cartridge further includes a first toner transporting member that transports toner supplied through the toner inlet in an axial direction of the supply roller, and a toner supply guide that is disposed between the first toner transporting member and the supply roller and includes a slit which has a length in the axial direction and through which toner is dropped onto the supply roller. The toner supply guide is downwardly inclined in the axial direction.

Provided is a waste toner container including a housing having a first reservoir and a second reservoir, a light sensor including a light emitting portion and a light receiving portion, and a light guide member to connect the light emitting portion with the light receiving portion. The light guide member includes a first detection portion and a second detection portion each including a pair of optical surfaces that are apart from each other, and the first and second detection portions are provided in the first and second reservoirs, respectively.

An image forming apparatus includes a toner cartridge, a light source, a light guiding device, and an optical sensor. The toner cartridge includes a developer member and a photosensitive member. The developer member receives toner and applies the toner to the photosensitive member. The light source emits light. The light guiding device guides the light from the light source at a plurality of areas on the developer member. The optical sensor detects an amount of reflected light reflected from the developer member.

An electrophotographic image forming apparatus may include a toner supply unit comprising a toner containing unit and a toner discharging unit having a toner outlet; a photoreceptor unit comprising a photoreceptor; a development unit comprising a development roller that supplies toner to develop the electrostatic latent image on the photoreceptor and a supply roller that supplies toner to the development roller; a first toner supply member that supplies toner of the toner containing unit to the toner discharging unit; and a second toner supply member that transports toner of the toner discharging unit to the toner outlet, wherein the first toner supply member is located in a second quadrant from among first through fourth quadrants based on a vertical line and a horizontal line which intersect at the second toner supply member, and wherein the photoreceptor, the supply roller, and the development roller are located in the fourth quadrant.