A sheet detecting device usable with a sheet feeding device for feeding a sheet, the sheet detecting device includes a common light emitter; a first light receptor and a second light receptor for receiving the light emitted by the common light emitter and output a signal in response to the reception of the light; a first detector configured to detect presence or absence of the sheet by switching the signal outputted by light receptor, in response to the sheet blocking or reflecting the light emitted by the common light emitter; a movable portion capable of being moved by the sheet which is moving; and a second detector configured to detect presence or absence of the sheet by switching the signal outputted by the second light receptor, in response to the movable portion forming or blocking a optical path for the light emitted by the common light emitter.

A detector, which is included in a sheet feeding device, a sheet conveying device, an image forming apparatus and an image reading device, contacts and detects a sheet, and includes a base, a sheet contact face to which the sheet contacts, and a coat layer formed on the sheet contact face. A difference of a static coefficient of friction s of the coat layer and a kinetic coefficient of friction d of the coat layer is smaller than and equal to 0.12.

A sheet detecting device usable with a sheet feeding device for feeding a sheet, the sheet detecting device includes a common light emitter; a first light receptor and a second light receptor for receiving the light emitted by the common light emitter and output a signal in response to the reception of the light; a first detector configured to detect presence or absence of the sheet by switching the signal outputted by light receptor, in response to the sheet blocking or reflecting the light emitted by the common light emitter; a movable portion capable of being moved by the sheet which is moving; and a second detector configured to detect presence or absence of the sheet by switching the signal outputted by the second light receptor, in response to the movable portion forming or blocking a optical path for the light emitted by the common light emitter.

An image forming apparatus includes a developing container, a detection portion detecting an amount of toner in the developing container, a display portion, and a control portion controlling the detection portion to execute a first detection and a second detection, wherein the display portion, in a case where the detection result of the first detection is greater than or equal to a first threshold, displays a first display and, in a case where the detection result is less than the first threshold, displays a second display different from the first display, and in a case where the detection result of the second detection is greater than or equal to a second threshold smaller than the first threshold, displays the first display and, in a case where the detection result is less than the second threshold, displays the second display.

A sheet supporting device comprises a first supporting unit, a second supporting unit provided to the first supporting unit and drawable in a draw direction from an insert position, a supporting portion on which sheets are supported and provided ascendably/descendably in the first supporting unit, first and second turning portions configured to turn in linkage with an ascendance and descendance move of the supporting portion, an elevation portion, and an indicator. The elevation portion, whose one end is connected with the first turning portion and another end is connected with the second turning portion, is configured to form a link mechanism together with the first and second turning portions and the first supporting unit. The indicator is provided in the second supporting unit and indicates an amount of the sheets supported on the supporting portion by moving in response to an ascendance and descendance move of the elevation portion.

A sheet conveyance apparatus includes an apparatus main body, an opening/closing door movably supported by the apparatus main body so as to be capable of opening a conveyance path through which a sheet is conveyed, a sensor lever configured to rotate when pushed by the sheet in the conveyance path, a holder rotatably holding the sensor lever and movably supported by the opening/closing door, a positioning portion provided in the apparatus main body and configured to perform positioning of the holder by coming into contact with the holder, and a sheet detection sensor provided in the apparatus main body and configured to generate a signal corresponding to the position of the sensor lever.

An image forming apparatus includes a developing container, a detection portion detecting an amount of toner in the developing container, a display portion, and a control portion controlling the detection portion to execute a first detection and a second detection, wherein the display portion, in a case where the detection result of the first detection is greater than or equal to a first threshold, displays a first display and, in a case where the detection result is less than the first threshold, displays a second display different from the first display, and in a case where the detection result of the second detection is greater than or equal to a second threshold smaller than the first threshold, displays the first display and, in a case where the detection result is less than the second threshold, displays the second display.

A sheet supporting device comprises a first supporting unit, a second supporting unit provided to the first supporting unit and drawable in a draw direction from an insert position, a supporting portion on which sheets are supported and provided ascendably/descendably in the first supporting unit, first and second turning portions configured to turn in linkage with an ascendance and descendance move of the supporting portion, an elevation portion, and an indicator. The elevation portion, whose one end is connected with the first turning portion and another end is connected with the second turning portion, is configured to form a link mechanism together with the first and second turning portions and the first supporting unit. The indicator is provided in the second supporting unit and indicates an amount of the sheets supported on the supporting portion by moving in response to an ascendance and descendance move of the elevation portion.

An image forming apparatus includes an image forming unit, a casing, a door, a connecting member, a guide member, and an operating portion. The operating portion moves, through an operation by a user when the door is at a first opened position, from a regulating position where the connecting member is regulated from moving from a first guide to a second guide, to an allowing position where the connecting member is allowed to move from the first guide to the second guide. When the operating portion is at the regulating position, the door is configured to be retained at the first opened position by engagement of the connecting member and the first guide. When the operating portion is at the allowing position, the door is configured to be retained at the second opened position by movement of the connecting member from the first guide to the second guide.

A sheet conveying device includes a body, a first guide in the body, a cover, a second guide in the cover, a detector, and a positioner. The first and second guides form a conveyance path at a closed state of the cover. The detector detects a sheet in the conveyance path and includes a photosensor in the body and a feeler in the cover. The feeler includes a detected portion movable in conjunction with the sheet passing through the conveyance path and a contacted portion. The photosensor has a detection region in which the detected portion entering the detection region is detected. The positioner in the body contacts the contacted portion to position the detected portion in the detection region.