US-20260126745-A1 - MEDIA DETECTION APPARATUS, IMAGE FORMING SYSTEM, AND RECORDING MEDIUM

US20260126745A1US 20260126745 A1US20260126745 A1US 20260126745A1US-20260126745-A1

Abstract

A media detection apparatus for detecting moisture information corresponding to a moisture amount or a moisture percentage of a sheet, the media detection apparatus including: a moisture sensor including a light emitter that emits light and a light receiver that receives the light reflected off the sheet or transmitted through the sheet; and a hardware processor that controls a temperature of the light emitter such that a wavelength of the light emitted from the light emitter becomes a predetermined wavelength.

Inventors

Hitoshi Asano
Kenji Izumiya
Hiroshi Oyama
Akira Okamoto
Masayuki Watanabe
SHOTA IGO
Hiroshi Yamaguchi

Assignees

Konica Minolta, Inc.

Dates

Publication Date: 20260507
Application Date: 20251105
Priority Date: 20241106

Claims (14)

1 . A media detection apparatus for detecting moisture information corresponding to a moisture amount or a moisture percentage of a sheet, the media detection apparatus comprising: a moisture sensor including a light emitter that emits light and a light receiver that receives the light reflected off the sheet or transmitted through the sheet; and a hardware processor that controls a temperature of the light emitter such that a wavelength of the light emitted from the light emitter becomes a predetermined wavelength.
2 . The media detection apparatus according to claim 1 , wherein the hardware processor controls the temperature of the light emitter during detection of the moisture information based on a measurement result by a temperature sensor disposed near the light emitter.
3 . The media detection apparatus according to claim 1 , further comprising at least one of a heater that heats the light emitter and a cooler that cools the light emitter.
4 . The media detection apparatus according to claim 3 , wherein the hardware processor heats the light emitter by passing a current through a resistor included in the heater, the resistor being disposed near the light emitter.
5 . The media detection apparatus according to claim 3 , wherein the hardware processor cools the light emitter with at least one of a fan motor and a Peltier element included in the cooler.
6 . The media detection apparatus according to claim 1 , wherein the light emitter includes a light emitting diode or a laser diode.
7 . The media detection apparatus according to claim 1 , wherein the hardware processor controls the temperature of the light emitter based on temperature characteristic information indicating a correspondence relationship between the wavelength of the light and the temperature of the light emitter for each light emitting element of the light emitter.
8 . The media detection apparatus according to claim 7 , further comprising a storage that stores the temperature characteristic information.
9 . The media detection apparatus according to claim 1 , wherein the hardware processor controls the temperature of the light emitter before detection of the moisture information.
10 . The media detection apparatus according to claim 9 , wherein the hardware processor controls the temperature of the light emitter by supplying a current to a light emitting element of the light emitter when the moisture information is not detected.
11 . The media detection apparatus according to claim 9 , wherein the hardware processor controls the temperature of the light emitter by changing a duty ratio of a current to be supplied to a light emitting element of the light emitter when the moisture information is not detected.
12 . The media detection apparatus according to claim 9 , wherein the hardware processor controls the temperature of the light emitter during detection of the moisture information based on a measurement result by a temperature sensor disposed near the light emitter or a measurement result of an environmental temperature.
13 . An image forming system comprising: the media detection apparatus according to claim 1 ; and an image former capable of forming an image on the sheet.
14 . A non-transitory recording medium storing a computer readable program for a computer of a media detection apparatus for detecting moisture information corresponding to a moisture amount or a moisture percentage of a sheet, the media detection apparatus including a moisture sensor including: a light emitter that emits light; and a light receiver that receives the light reflected off the sheet or the light transmitted through the sheet, and the program causing the computer to perform controlling a temperature of the light emitter such that a wavelength of the light emitted from the light emitter becomes a predetermined wavelength.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The entire disclosure of Japanese Patent Application No. 2024-194136 filed on Nov. 6, 2024 is incorporated herein by reference in its entirety. BACKGROUND OF THE INVENTION Technical Field The present disclosure relates to a media detection apparatus, an image forming system, and a recording medium. Description of Related Art In a conventionally known image forming apparatus, a media sensor is installed partway along a conveyance path of a sheet, and characteristic values of a sheet transported along the conveyance path are detected by the media sensor. Next, the image forming apparatus determines image formation condition in accordance with the characteristic value of the sheet detected by the media sensor, and forms an image on the sheet. When the moisture percentage of a sheet is measured using a moisture sensor as a media sensor, the measurement result may change although the sheet is in the same state. This is because the moisture sensitivity changes as the wavelength of the light emitted by the light emitting section changes due to a change in the temperature of the light emitting section caused by a temperature increase or the like due to self-heating of the light emitting section (LED or the like) itself included in the moisture sensor. Due to such a phenomenon, there is a problem that an error occurs in the moisture percentage of the sheet detected by the moisture sensor with respect to the original moisture percentage of the sheet. For example, Japanese Unexamined Patent Publication No. 2024-115578 describes that, for the above-described phenomenon, the moisture percentage of the sheet detected by the moisture sensor is corrected based on the temperature of the light emitting section and correction values set in advance for respective representative paper types such as plain paper and thick paper. SUMMARY OF THE INVENTION However, the change characteristics of the light absorptivity due to the moisture in the sheet differ depending on the composition, sheet thickness, color, surface shape, and the like of the sheet. Therefore, in a case where the moisture percentage of the sheet detected by the moisture sensor is corrected based on the correction value corresponding to the representative paper type as in the invention described in Japanese Unexamined Patent Publication No. 2024-115578, there is a problem that it is difficult to perform sufficient correction for all the paper types. An object of the present disclosure is to provide a media detection apparatus, an image forming system, and a recording medium that can more accurately detect moisture information corresponding to the moisture amount or the moisture percentage of a sheet. To achieve at least one of the abovementioned objects, according to an aspect of the present invention, a media detection apparatus reflecting one aspect of the present invention is a media detection apparatus for detecting moisture information corresponding to a moisture amount or a moisture percentage of a sheet, the media detection apparatus comprising:a moisture sensor including a light emitter that emits light and a light receiver that receives the light reflected off the sheet or transmitted through the sheet; anda hardware processor that controls a temperature of the light emitter such that a wavelength of the light emitted from the light emitter becomes a predetermined wavelength. BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features provided by one or more embodiments of the invention will become more fully understood from the detailed description given hereinbelow and the appended drawings which are given by way of illustration only, and thus are not intended as a definition of the limits of the present invention, wherein: FIG. 1 is a diagram illustrating a schematic configuration of an image forming system according to the present embodiment; FIG. 2 is a block diagram illustrating a main functional configuration of the image forming system according to the present embodiment; FIG. 3 is a diagram illustrating a schematic configuration of a moisture sensor; FIG. 4 is a diagram illustrating an example of the arrangement of the moisture sensor and the heating section; FIG. 5 is a diagram illustrating an example of the arrangement of the moisture sensor and the heating section; FIG. 6 is a diagram illustrating an example of the arrangement of the moisture sensor and the heating section; FIG. 7 is a diagram illustrating an example of temperature characteristic information; FIG. 8 is a flowchart showing a flow of a temperature control processing executed by the image forming system; and FIG. 9 is a flowchart illustrating the flow of temperature control processing of a modification example. DETAILED DESCRIPTION Hereinafter, one or more embodiments of the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the disclosed embodiments. Embodiments of an i