US-12619184-B2 - Image forming apparatus including cleaning portion that performs cleaning of sensing surface of sensor for outputting sensing value related to toner density

US12619184B2US 12619184 B2US12619184 B2US 12619184B2US-12619184-B2

Abstract

An image forming apparatus includes a density sensing portion, a cleaning portion, and a control portion. The density sensing portion includes a substrate and a sensor package and outputs a sensing value related to a toner density of a toner image formed on an outer circumferential surface of an image carrier. The control portion performs control so that, when the cleaning portion performs cleaning of a sensing surface, a brush is moved to a cleaning position where the brush contacts the sensing surface. The control portion also performs control so that, when the cleaning portion does not perform the cleaning of the sensing surface, the brush is moved to a retracted position where the brush does not contact the sensor package and the substrate.

Inventors

Takuro MORITA

Assignees

KYOCERA DOCUMENT SOLUTIONS INC.

Dates

Publication Date: 20260505
Application Date: 20250103
Priority Date: 20240112

Claims (3)

1 . An image forming apparatus, comprising: a density sensing portion including a sensor that applies light toward an outer circumferential surface of an image carrier and receives reflected light from the image carrier, the density sensing portion outputting a sensing value related to a toner density of a toner image formed on the outer circumferential surface of the image carrier; a cleaning portion including a brush that moves in an intersecting direction intersecting with the light applied by the sensor, the cleaning portion performing cleaning of a sensing surface of the sensor by use of the brush; and a control portion that controls an operation of the cleaning portion, wherein the density sensing portion includes: a substrate; and a sensor package that is secured to a surface of the substrate opposed to the image carrier so as to protrude toward the image carrier and holds the sensor, the cleaning portion includes: a slide member that holds the brush; a cleaning drive part that drives the slide member to move in the intersecting direction; and the brush that is secured to the slide member so as to protrude toward the sensor and has a length long enough to contact the sensing surface and not long enough to contact the substrate, the control portion performs control so that, when the cleaning portion performs the cleaning of the sensing surface, the brush is moved to a cleaning position where the brush contacts the sensing surface, and when the cleaning portion does not perform the cleaning of the sensing surface, the brush is moved to a retracted position where the brush does not contact the sensor package and the substrate, the density sensing portion includes a connector that is secured to the surface of the substrate opposed to the image carrier at a distance from the sensor package and is electrically connected to the sensor, and the retracted position of the brush is arranged between the sensor package and the connector.
2 . The image forming apparatus according to claim 1 , wherein the retracted position of the brush is arranged laterally adjacently to the sensor package.
3 . The image forming apparatus according to claim 1 , wherein the density sensing portion includes a securing member for securing the substrate, and the securing member is arranged at the retracted position of the brush so as not to contact the brush.

Description

INCORPORATION BY REFERENCE This application is based upon and claims the benefit of priority from the corresponding Japanese Patent Application No. 2024-003495 filed on Jan. 12, 2024, the entire contents of which are hereby incorporated by reference. BACKGROUND The present disclosure relates to an image forming apparatus. In electrophotographic image forming apparatuses such as a copy machine and a printer, there is widely used a device that supplies toner to an electrostatic latent image formed on an outer circumferential surface of a photosensitive drum so as to develop the electrostatic latent image into a toner image to be transferred later to a sheet. A density of a toner image formed by such an image forming apparatus may vary with time due to various reasons. That is why calibration is generally executed in which a toner image for density correction (a reference image) is formed on an outer circumferential surface of a photosensitive drum or an intermediate transfer belt (an image carrier), and a toner density of the toner image sensed by a sensor is corrected. In order to properly perform the density correction, what is important is a cleaning process to remove foreign matter adhering to a sensing surface of the sensor. SUMMARY An image forming apparatus according to one aspect of the present disclosure includes a density sensing portion, a cleaning portion, and a control portion. The density sensing portion includes a sensor that applies light toward an outer circumferential surface of an image carrier and receives reflected light from the image carrier, and outputs a sensing value related to a toner density of a toner image formed on the outer circumferential surface of the image carrier. The cleaning portion includes a brush that moves in an intersecting direction intersecting with the light applied by the sensor, and performs cleaning of a sensing surface of the sensor by use of the brush. The control portion controls an operation of the cleaning portion. The density sensing portion includes a substrate and a sensor package that is secured to a surface of the substrate opposed to the image carrier so as to protrude toward the image carrier and holds the sensor. The cleaning portion includes a slide member that holds the brush, a drive part that drives the slide member to move in the intersecting direction, and the brush that is secured to the slide member so as to protrude toward the sensor and has a length long enough to contact the sensing surface and not long enough to contact the substrate. The control portion performs control so that, when the cleaning portion performs the cleaning of the sensing surface, the brush is moved to a cleaning position where the brush contacts the sensing surface, and when the cleaning portion does not perform the cleaning of the sensing surface, the brush is moved to a retracted position where the brush does not contact the sensor package and the substrate. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic sectional front view of an image forming apparatus according to one embodiment of the present disclosure. FIG. 2 is a block diagram illustrating a configuration of the image forming apparatus shown in FIG. 1. FIG. 3 is a schematic sectional front view of and around image forming portions in the image forming apparatus shown in FIG. 1. FIG. 4 is a schematic sectional side view of and around a density sensing portion shown in FIG. 3. FIG. 5 is a partially enlarged sectional side view of the density sensing portion shown in FIG. 4. FIG. 6 is a partially enlarged sectional side view of a sensor part of the density sensing portion shown in FIG. 4, illustrating a state where a brush of a cleaning portion has been moved to a cleaning position. FIG. 7 is a perspective view of the sensor part of the density sensing portion shown in FIG. 4. DETAILED DESCRIPTION With reference to the appended drawings, the following describes an embodiment of the present disclosure. The present disclosure, however, is not limited to what is described below. FIG. 1 is a schematic sectional front view of an image forming apparatus 1 according to the embodiment. FIG. 2 is a block diagram illustrating a configuration of the image forming apparatus 1 shown in FIG. 1. FIG. 3 is a schematic sectional front view of and around image forming portions 20 in the image forming apparatus 1 shown in FIG. 1. One example of the image forming apparatus 1 according to this embodiment is a tandem color printer that uses an intermediate transfer belt 31 to transfer a toner image to a sheet S. The image forming apparatus 1 may be a so-called multifunctional peripheral equipped with functions such as, for example, printing, scanning (image reading), facsimile transmission, and so on. As shown in FIGS. 1, 2, and 3, the image forming apparatus 1 includes, in a main body 2 thereof, a sheet feed portion 3, a sheet conveyance portion 4, an exposure portion 5, the image forming portions 20, a transfer portion