A sheet binding device includes a first tooth-shaped member that has plural arranged teeth, and a second tooth-shaped member that has plural arranged teeth, bites the first tooth-shaped member to clamp and bind sheets in cooperation with the first tooth-shaped member, and is tilted relative to the first tooth-shaped member from a beginning of biting to a completion of biting.

A sheet binding device includes a binding operation unit including a first tooth-shaped member that has plural arrayed teeth, a second tooth-shaped member that has plural arrayed teeth and binds sheets by biting the first tooth-shaped member to clamp the sheets in cooperation with the first tooth-shaped member, and a link structure that opens and closes the first tooth-shaped member and the second tooth-shaped member to perform a binding operation, and two side frames that are arranged to hold the binding operation unit therebetween and to support the binding operation unit on both sides of the binding operation unit.

A sheet binding device includes a binding operation unit including a first tooth-shaped member that has plural arrayed teeth, a second tooth-shaped member that has plural arrayed teeth and binds sheets by biting the first tooth-shaped member to clamp the sheets in cooperation with the first tooth-shaped member, and a link structure that opens and closes the first tooth-shaped member and the second tooth-shaped member to perform a binding operation, and two side frames that are arranged to hold the binding operation unit therebetween and to support the binding operation unit on both sides of the binding operation unit.

A booklet forming device includes a sheet support portion, and a bonding unit including a pressurizing member and configured to form a bonding layer. In a case of forming a first booklet including a first number of sheets, the bonding unit is operated under a first operation condition so that a thickness of the bonding layer positioned closest to the pressurizing member in the first booklet becomes a first thickness. In a case of forming a second booklet including a second number of sheets more than the first number of sheets, the bonding unit is operated under a second operation condition different from the first operation condition so that the thickness of the bonding layer positioned closest to the pressurizing member in the second booklet becomes a second thickness larger than the first thickness.

A medium processing apparatus includes: a binder to bind multiple sheets at a binding position to form a sheet bundle; a sheet inserter having an opening into which the sheet bundle is insertable from an outside of the sheet inserter to a bindable region having the binding position; and a binding position verifier allowing the multiple sheets, inserted from the opening to the bindable region, to be verifiable from an outside of the sheet inserter.

An image forming apparatus at least comprising: first image forming means for forming a first adhesive layer of a first toner on a sheet; and second image forming means for forming a second adhesive layer of a second toner on the first adhesive layer, adhesive image patterns are formed from the first and the second adhesive layer, the image forming apparatus further comprising specific booklet bonding means, wherein at least both the first and the second adhesive layer are formed on one of a first sheet and a second sheet that face each other in the sheet bundle, at least the first adhesive layer is formed on the other of the first sheet and the second sheet, and G1>G2 is satisfied, where G1 denotes a storage elastic modulus of the first toner, and G2 denotes a storage elastic modulus of the second toner.

An image forming apparatus at least comprising: first image forming means for forming a first adhesive layer of a first toner on a sheet; and second image forming means for forming a second adhesive layer of a second toner on the first adhesive layer, adhesive image patterns are formed from the first and the second adhesive layer, the image forming apparatus further comprising specific booklet bonding means, wherein at least both the first and the second adhesive layer are formed on one of a first sheet and a second sheet that face each other in the sheet bundle, at least the first adhesive layer is formed on the other of the first sheet and the second sheet, and G1>G2 is satisfied, where G1 denotes a storage elastic modulus of the first toner, and G2 denotes a storage elastic modulus of the second toner.

An image forming apparatus comprises a rotationally driven photosensitive body, a charging device that charges a surface of the photosensitive body, an exposure light source that forms an electrostatic latent image by exposing the surface of the photosensitive body to light, a developing device that forms a toner image by developing the electrostatic latent image using toner, a transfer member that transfers the toner image to a sheet, a first memory that stores a cumulative image formation amount for each one of N exposure regions, and a control circuit that controls the exposure light source.

A sheet thermocompression apparatus for bonding a plurality of the sheets to one another, and configured to be compatible with the sheets with a plurality of prescribed sizes. The apparatus includes a loading portion to be loaded with the bundle of sheets each including the adhesion layer formed thereon and a thermocompression unit. The thermocompression unit includes (i) a pressing member pressing the bundle of sheets loaded on the loading portion in a loading direction of the sheets, a longitudinal direction of the pressing member is a direction along one edge of the sheets loaded on the loading portion, (ii) a heating source heating the pressing member, and (iii) a temperature measuring sensor arranged at a position not overlapping a minimum sheet with a minimum size of the prescribed sizes loaded on the loading portion in the loading direction, and detects a temperature of the heating source.

A sheet thermocompression apparatus for bonding a plurality of the sheets to one another, and configured to be compatible with the sheets with a plurality of prescribed sizes. The apparatus includes a loading portion to be loaded with the bundle of sheets each including the adhesion layer formed thereon and a thermocompression unit. The thermocompression unit includes (i) a pressing member pressing the bundle of sheets loaded on the loading portion in a loading direction of the sheets, a longitudinal direction of the pressing member is a direction along one edge of the sheets loaded on the loading portion, (ii) a heating source heating the pressing member, and (iii) a temperature measuring sensor arranged at a position not overlapping a minimum sheet with a minimum size of the prescribed sizes loaded on the loading portion in the loading direction, and detects a temperature of the heating source.