Abstract: An image forming apparatus of the present disclosure includes: an image carrier configured to carry toner patches; a first sensor configured to irradiate S-polarized light to a low-density patch in a predetermined low density range among the toner patches, and to receive reflection light from the low-density patch; and a second sensor configured to irradiate P-polarized light to a high-density patch in a predetermined high density range among the toner patches, and to receive reflection light from the high-density patch.

Abstract: An embodiment of an image forming apparatus may include a photosensitive member, a development unit, a transfer member, a sensor, and a correcting unit. The development unit may form a toner image on the photosensitive member. The toner image member may be transferred onto the transfer member. The sensor may detect light from a surface of the transfer member. The correcting unit may correct a toner density in a first area of the transfer member after transfer of a toner image of a test pattern to the first area. The correcting unit may correct the toner density on the basis of a difference between an output value of the sensor from a second area before the transfer of the toner image of the test pattern and an output value of the sensor from the second area after the transfer of the toner image of the test pattern.

Abstract: An image forming apparatus including an image carrying member, a detecting section, and a linear-speed deriving section. The image carrying member carries a toner image. The detecting section detects passages of a mark, provided on the image carrying member, at a plurality of predetermined detection positions. The linear-speed deriving section determines a linear speed of the image carrying member from times at which the detecting section detects the passage of the mark.

Abstract: An embodiment of an image forming apparatus may include a photosensitive member, a development unit, a transfer member, a sensor, and a correcting unit. The development unit may form a toner image on the photosensitive member. The toner image member may be transferred onto the transfer member. The sensor may detect light from a surface of the transfer member. The correcting unit may correct a toner density in a first area of the transfer member after transfer of a toner image of a test pattern to the first area. The correcting unit may correct the toner density on the basis of a difference between an output value of the sensor from a second area before the transfer of the toner image of the test pattern and an output value of the sensor from the second area after the transfer of the toner image of the test pattern.

Abstract: A controller takes in a detection signal indicating the surface electrical potential of a photoconductive drum (7) from a surface electrical potential sensor (step #1), and determines whether the surface electrical potential is smaller than the predetermined threshold value (step #2). As a result, when the controller (6) determines that the surface electrical potential is equal to or greater than the predetermined threshold value (NO in step #2), it uses the low print rate density patch to execute the density adjustments in accordance with the toner density and the developing bias associated with the density patch (step #3). When the controller (6) determines that the surface electrical potential is smaller than the predetermined threshold value (NO in step #1), it uses a high print rate density patch to execute the density adjustments in accordance with the toner density and the developing bias associated with the density patch (step #4).

Abstract: A controller takes in a detection signal indicating the surface electrical potential of a photoconductive drum (7) from a surface electrical potential sensor (step #1), and determines whether the surface electrical potential is smaller than the predetermined threshold value (step #2). As a result, when the controller (6) determines that the surface electrical potential is equal to or greater than the predetermined threshold value (NO in step #2), it uses the low print rate density patch to execute the density adjustments in accordance with the toner density and the developing bias associated with the density patch (step #3). When the controller (6) determines that the surface electrical potential is smaller than the predetermined threshold value (NO in step #1), it uses the high print rate density patch to execute the density adjustments in accordance with the toner density and the developing bias associated with the density patch (step #4).