Abstract: Disclosed herein is a short arc discharge lamp which has a cathode electrode structure formed by solid-phase bonding a tip part made of thoriated tungsten to a body part made of tungsten. According to the present invention, the bonding strength between the body part and the tip part is increased to the same level as the mechanical strength of tungsten, thus preventing a breakage from being caused on a junction interface. For this, on a section of the cathode electrode taken along a line perpendicular to the junction interface, in an arbitrary portion of 500 ?m or more in length along the junction interface, when a length of the arbitrary portion along the junction interface is set to L0, and a sum of lengths of tungsten crystal grains, along the junction interface, that are present through the junction interface is set to L, (L/L0)?0.16 is satisfied.

Abstract: Disclosed herein is a short arc discharge lamp which has a cathode electrode structure formed by solid-phase bonding a tip part made of thoriated tungsten to a body part made of tungsten. According to the present invention, the bonding strength between the body part and the tip part is increased to the same level as the mechanical strength of tungsten, thus preventing a breakage from being caused on a junction interface. For this, on a section of the cathode electrode taken along a line perpendicular to the junction interface, in an arbitrary portion of 500 ?m or more in length along the junction interface, when a length of the arbitrary portion along the junction interface is set to L0, and a sum of lengths of tungsten crystal grains, along the junction interface, that are present through the junction interface is set to L, (L/L0)?0.16 is satisfied.

Abstract: A xenon short arc lamp for a digital projector, includes an anode, a cathode having a cathode main body that is made of tungsten containing electron emissive material, and an arc tube made of silica glass, wherein a supply source of carbon is formed on a metal portion in the arc tube except a tip area of the cathode, and the carbon is supplied to the tip of the cathode through a gaseous phase during lamp lighting, so that a surface layer of the cathode is melt.

Abstract: A xenon short arc lamp for a digital projector, includes an anode, a cathode having a cathode main body that is made of tungsten containing electron emissive material, and an arc tube made of silica glass, wherein a supply source of carbon is formed on a metal portion in the arc tube except a tip area of the cathode, and the carbon is supplied to the tip of the cathode through a gaseous phase during lamp lighting, so that a surface layer of the cathode is melt.

Abstract: An image forming apparatus having excellent cleaning property for an electrophotographic photoreceptor and capable of forming a high-quality, high-resolution image. A surface free energy (?) of a photoreceptor (2), which is provided in the image forming apparatus (1), is set to 20 to 35 mN/m. A volume average diameter of toner particles included in a developer stored in a developing unit (29) to develop an electrostatic latent image and form a toner image is set to 4-7 ?m When ? of the photoreceptor (2) is set to within a small range as the particle size of toner is reduced, even small-particle-size toner having increased specific surface area and largely affected by a inter-molecular force is limited in adhesion to the surface of the photoreceptor (2) to provide a good cleaning property and a high-quality image can be formed.

Abstract: An object of the invention is to provide an image forming apparatus being excellent in cleaning property for an electrophotographic photoreceptor and capable of forming a high-quality, high-resolution image. A surface free energy (?) of a photoreceptor (2) which is provided in the image forming apparatus (1) and is exposed to a light corresponding to image information for formation of an electrostatic latent image is set to 20 to 35 mN/m. A volume average diameter of a toner particles included in a developer stored in a developing unit (29) to develop an electrostatic latent image and form a toner image is set to 4-7 mum.

Abstract: An electrophotographic photoreceptor having good electric properties such as chargeability, sensitivity and responsibility, having good oxidizing gas resistance, and having good property stability in that the good electric properties thereof do not worsen in repeated use, is provided. An undercoat layer is provided between the conductive support and the photosensitive layer of an electrophotographic photoreceptor, and the undercoat layer contains an amine compound expressed by the following formula (1) added thereto.