Abstract: An image forming apparatus includes a mounting portion, an accommodating portion, a remaining toner amount detecting portion, a display portion, and a controller. In a supplying operation, the controller sets a threshold changing on the basis of a first output value before toner supply from the toner container to the accommodating portion. The controller discriminates whether or not toner in a certain amount or more is supplied to the accommodating portion by comparing the threshold with a second output value after the toner is supplied from the toner container to the accommodating portion. The threshold is a value between the first output value and a third output value in when the toner in a total amount accommodated in the toner container that has never been used is supplied to the accommodating portion before supply of the toner, and is closer to the third value than to the first value.

Abstract: An image forming apparatus includes an apparatus body, an image bearing member, and a process unit attached to the apparatus body, the process unit including a frame including a storage portion configured to store developer, a developer bearing member configured to supply developer to the image bearing member to develop an electrostatic latent image; and a circuit board attached to the frame, wherein the circuit board includes a light emitting portion configured to emit light, and a light receiving portion configured to receive the light emitted from the light emitting portion and having passed through an interior of the storage portion.

Abstract: The shift response in a V-belt type automatic transmission is improved using a double cogged V-belt having an endless core wire embedded portion in which core wires are embedded, a lower cog formed portion provided over the inner circumference of the core wire embedded portion, and an upper cog formed portion provided over the outer circumference of the core wire embedded portion, as a V-belt for transmitting power from a drive pulley device to a driven pulley device. Each of the core wires is formed from aramid fibers, and the ratio (W/T) of the width W of the V-belt to the thickness T of the V-belt is set to 2.5 or less.