Image forming apparatus

An electrophotographic image forming apparatus comprising:

• a first photosensitive member;
• a first developing roller configured to supply toner to the first photosensitive member and form a toner image on the first photosensitive member;
• a second photosensitive member;
• a second developing roller configured to supply powder adhesive to the second photosensitive member and form an adhesive layer on the second photosensitive member;
• a transfer unit configured to transfer the toner image and the adhesive layer to a sheet by applying transfer voltage to the toner image and the adhesive layer;
• a pair of rotatable fixing members configured to fix the toner image and the adhesive layer formed on the sheet onto the sheet, the pair of rotatable fixing members being configured to heat the sheet at a fixing nip portion formed by the pair of rotatable fixing members while conveying the sheet at the fixing nip portion;
• a plurality of rollers configured to fold the sheet having passed through the pair of rotatable fixing members such that a surface of the sheet to which the adhesive layer is formed is folded to become opposing inner surfaces of the folded sheet;
• and
• a pair of rotatable members configured to bond the opposing inner surfaces of the folded sheet together by the adhesive layer, the pair of rotatable members being configured to heat the folded sheet from an outside of the folded sheet at a heating nip portion formed by the pair of rotatable members while conveying the folded sheet at the heating nip portion,
• wherein the pair of rotatable fixing members and the pair of rotatable members are configured such that a relationship of Tmax1>Tmax2 is satisfied, where Tmax1 (° C.) is a highest temperature of the adhesive layer when being heated by the pair of rotatable fixing members and Tmax2 (° C.) is a highest temperature of the adhesive layer when being heated by the pair of rotatable members, and
• wherein a relationship of Q1<Q2 is satisfied, where Q1 (J/mm2) is a heat quantity per unit area applied to the sheet by the pair of rotatable fixing members and Q2 (J/mm2) is a heat quantity per unit area applied to the folded sheet by the pair of rotatable members.

An electrophotographic image forming system comprising:

• an electrophotographic printer including:
• a first photosensitive member,
• a first developing roller configured to supply toner to the first photosensitive member and form a toner image on the first photosensitive member,
• a second photosensitive member,
• a second developing roller configured to supply powder adhesive to the second photosensitive member and form an adhesive layer on the second photosensitive member,
• a transfer unit configured to transfer the toner image and the adhesive layer to a sheet by applying transfer voltage to the toner image and the adhesive layer, and
• a pair of rotatable fixing members configured to fix the toner image and the adhesive layer formed on the sheet onto the sheet, the pair of rotatable fixing members configured to heat the sheet at a fixing nip portion formed by the pair of rotatable fixing members while conveying the sheet at the fixing nip portion;
• and
• a postprocessing unit attached to the printer, the postprocessing unit including:
• a plurality of rollers configured to fold the sheet having passed through the pair of rotatable fixing members such that a surface of the sheet to which the adhesive layer is formed is folded to become opposing inner surfaces of the folded sheet;
• and
• a pair of rotatable members configured to bond the opposing inner surfaces of the folded sheet together by the adhesive layer, the pair of rotatable members configured to heat the folded sheet from an outside of the folded sheet at a heating nip portion formed by the pair of rotatable members while conveying the folded sheet at the heating nip portion,
• wherein the pair of rotatable fixing members and the pair of rotatable members are configured such that a relationship of Tmax1>Tmax2 is satisfied, where Tmax1 (° C.) is a highest temperature of the adhesive layer when being heated by the pair of rotatable fixing members and Tmax2 (° C.) is a highest temperature of the adhesive layer when being heated by the pair of rotatable members, and
• wherein a relationship of Q1<Q2 is satisfied, where Q1 (J/mm2) is a heat quantity per unit area applied to the sheet by the pair of rotatable fixing members and Q2 (J/mm2) is a heat quantity per unit area applied to the folded sheet by the pair of rotatable members.

An electrophotographic image forming apparatus comprising:

• a photosensitive member;
• a developing roller configured to supply powder adhesive to the photosensitive member and form an adhesive layer on the photosensitive member;
• a transfer unit configured to transfer the adhesive layer to a sheet by applying transfer voltage to the adhesive layer;
• a pair of rotatable fixing members configured to fix the adhesive layer formed on the sheet onto the sheet, the pair of rotatable fixing members being configured to heat the sheet at a fixing nip portion formed by the pair of rotatable fixing members while conveying the sheet at the fixing nip portion;
• a plurality of rollers configured to fold the sheet having passed through the pair of rotatable fixing members such that a surface of the sheet to which the adhesive layer is formed is folded to become opposing inner surfaces of the folded sheet;
• and
• a pair of rotatable members configured to bond the opposing inner surfaces of the folded sheet together by the adhesive layer, the pair of rotatable members being configured to heat the folded sheet from an outside of the folded sheet at a heating nip portion formed by the pair of rotatable members while conveying the folded sheet at the heating nip portion,
• wherein the pair of rotatable fixing members and the pair of rotatable members are configured such that a relationship of Tmax1>Tmax2 is satisfied, where Tmax1 (° C.) is a highest temperature of the adhesive layer when being heated by the pair of rotatable fixing members and Tmax2 (° C.) is a highest temperature of the adhesive layer when being heated by the pair of rotatable members, and
• wherein a relationship of Q1<Q2 is satisfied, where Q1 (J/mm2) is a heat quantity per unit area applied to the sheet by the pair of rotatable fixing members and Q2 (J/mm2) is a heat quantity per unit area applied to the folded sheet by the pair of rotatable members.