An image forming apparatus is provided. The image forming apparatus includes an image forming part to form a pattern including at least one white dot line and at least one black dot line on an image forming medium using a photoconductive drum. A registration sensor is to sense an amount of light reflected from the image forming medium. A processor is to determine a state of the photoconductive drum based on the amount of sensed light in the pattern.

An image forming apparatus including an image forming device, a sensor, and a processor. The image forming device is to form an image on recording medium. The sensor is to irradiate light to the recording medium and detect an amount of light transmitted through the recording medium and an amount of light reflected from the recording medium, resulting in a control of a printing operation of the image forming device based the amount of light transmitted through the printing medium and the amount of light reflected from the printing medium.

A recording material characteristic detecting device that irradiates a first light and a second light to a recording material carried along a predetermined carrying path and detects a transmitted light generated when the first light transmits the recording material and a reflection light generated when the second light is reflected by the recording material, and detects a characteristic of the recording material, comprises: a reflection light source that irradiates the second light toward the carrying path; a reference plate for reflection light arranged oppositely to the reflection light source across the carrying path to reflect the second light; and a light detector arranged oppositely to the reference plate for reflection light across the carrying path to detect at least a reflection light generated in response to reflection of the second light. The reference plate has a higher reflectivity to the second light than a reflectivity to the first light.

Provided is a discriminating device including a light-receiving unit receiving light beam from a detected surface (DS) and an optical unit (OU) guiding light beam from DS to light-receiving unit, and satisfying following conditional expressions:
0.01|m1/m01|, and
1<|m1/m01|/|s1/s01|,
where m0 represents a magnification of OU with respect to a first direction in a first cross section parallel to DS when DS is at a first position, m1 represents a magnification of OU with respect to first direction in first cross section when DS is at a second position shifted from first position by +0.2 mm in a direction perpendicular to DS, s0 represents a magnification of OU with respect to a second direction perpendicular to first direction in first cross section when DS is at first position, and s1 represents a magnification of OU with respect to second direction in first cross section when DS is at second position.

A measuring device a measurement unit configured to measure an image on a sheet, the measurement unit including a light emitting portion configured to illuminate the sheet with light, and a detecting portion configured to detect light reflected by the sheet; a supporting unit supporting the measurement unit; and a driving unit configured to move the measurement unit supported by the supporting unit in a scanning direction. A size, in the scanning direction, of a detectable range of the detecting portion in which the detecting portion is capable of detecting the reflected light from the sheet is larger than a size, in a sub-scanning direction perpendicular to the scanning direction and a normal direction of a surface of the sheet, of the detectable range of the detecting portion.

Provided are a sheet position detection apparatus, a sheet conveyance apparatus, and an image formation apparatus. The sheet position detection apparatus has a first and a second conveyance roller which are arranged to oppose across a sheet to be conveyed and to nip the sheet, and a detector configured to detect an end position of the sheet, the detector has a light emitter and a light receptor arranged on the first conveyance roller side, the light emitter and the light receptor are arranged such that a light emitted from the light emitter is reflected on a reflective face of the second conveyance roller and enters the light receptor, and the detector detects passage of an end of the sheet based on a change in the amount of light entering the light receptor when the sheet shields a light emitted from the light emitter.

A sheet type determining device including a guide that guides a sheet along a sheet conveyance path to a destination. The sheet conveyance path is between a first guide surface and a second guide surface facing each other across an interval. The sheet type determining device further includes a determiner that determines a sheet type when the sheet is in the sheet conveyance path, without having contact with the sheet in conveyance, and one or more regulators that regulate a displacement range of the sheet at a determining position, the displacement range being in a direction of the interval of the first and the second guide surfaces. Each of the regulators is a member that protrudes in an arc shape from the first or the second guide surface toward the guide surface opposite, and is spaced from the guide surface or another one of the regulators opposite.

An image forming apparatus includes an optical sensor for detecting an image formed on an intermediate transfer belt. The optical sensor includes first and second light emitting diodes (LEDs) and first and second photodiodes (PDs). The first and second LEDs irradiate an optical-axis center point of an intermediate transfer belt. The first PD is arranged at a position at which an optical axis of specularly reflected light of light emitted from the second LED and an optical axis along which specularly reflected light of light emitted from the first LED is received form a first angle. The second PD is arranged at a position at which the optical axis of the specularly reflected light of the light emitted from the second LED and an optical axis along which diffused reflected light of the light emitted from the second LED is received form a second angle different from the first angle.

Provided is a discriminating device including a light-receiving unit receiving light beam from a detected surface (DS) and an optical unit (OU) guiding light beam from DS to light-receiving unit, and satisfying following conditional expressions:

0.01|m1/m01|, and

1<|m1/m01|/|s1/s01|,

where m0 represents a magnification of OU with respect to a first direction in a first cross section parallel to DS when DS is at a first position, m1 represents a magnification of OU with respect to first direction in first cross section when DS is at a second position shifted from first position by +0.2 mm in a direction perpendicular to DS, s0 represents a magnification of OU with respect to a second direction perpendicular to first direction in first cross section when DS is at first position, and s1 represents a magnification of OU with respect to second direction in first cross section when DS is at second position.

An image forming apparatus comprises a light-emission unit, a reflecting member, a light-receiving unit, a detection unit, a ventilation unit configured to send air to the reflecting member, and a control unit. The control unit adjusts at least one of an operation duration and an airflow rate of the ventilation unit, in accordance with a detection signal outputted by the light-receiving unit when a sheet is not at a position where light crosses a conveyance path.