PROBLEM TO BE SOLVED: To provide an on-bed state detection device for a bed and an on-bed state detection method by and with which an on-bed state of a user can be reliably detected.SOLUTION: An on-bed state detection device includes: area-setting means which sets a bed-rest area 30A where a gravity position G (GX, GY) of a user U exists when the user U takes a sleeping posture, and a seating area 30B comprising a region other than the bed-rest area 30A to a bed 30； a plurality of load-detection means which detects load applied on each end part of the bed 30； and on-bed state detection means which detects an on-bed state of the user U on the bed 30 on the basis of a plurality of output values W1 to W4 from the plurality of load detection means. The on-bed state detection means includes: on-bed state decision means which decides whether the user U on the bed 30 is in an on-bed state or in a seating state on the basis of the plurality of output values W1 to W4 after deciding which of the on-bed region 30A or the seating region 30B of the bed 30 the gravity position G (GX, GY) exist at.SELECTED DRAWING: Figure 2【課題】ベッド上の使用者の在床状態を確実に検知することができるベッド用在床状況検知装置及びベッドの在床状況検知方法を提供する。【解決手段】検知装置は、ベッド30を、使用者Uが就寝姿勢の時に使用者Uの重心位置G(GX,GY)が存在する臥床領域30Aと臥床領域30A以外の領域からなる着座領域30Bとに設定する領域設定手段と、ベッド30の各端部にそれぞれ掛かる荷重を検出する複数の荷重検出手段と、複数の荷重検出手段からの複数の出力値W1～W4に基づいてベッド30上の使用者Ｕの在床状況を検知する在床状況検知手段と、を含む。在床状況検知手段は、重心位置G(GX,GY)がベッド30の臥床領域30A及び着座領域30Bのうちどちらに存在するかを判定した後に、複数の出力値W1～W4に基づいて、ベッド30上の使用者Uが臥床状態であるか着座状態であるかを判定する在床状態判定手段と、を具備する。【選択図】図２
