Abstract: A switching element and a protective resistance are connected between a developing roller and a developing bias source. A switching element switches on and off a connection between the developing roller and the developing bias source. A protective resistance is connected to the switching element in series. There is a controller and a bias stabilizer. The controller switches on the switching element when a developing bias voltage is to be applied to the developing roller and switches off the switching element when the developing roller is caused to be in an electrically floating state without applying the developing bias voltage, and which bias stabilizer is disposed between the developing roller and a ground and maintains a predetermined stable voltage only when the switching element is switched on. The structure enables a high-quality image to be formed with a low power consumption.

Abstract: To prevent scattering of toner when an image forming operation is started and ended in a developing process using one-component toner, a rotatable developing roller in contact with a photosensitive member carrying a static latent image, which is used to carry and feed one-component toner, is provided in a developing tank containing one-component toner. Initially, toner is fed to a feed roller, then passed through a toner restricting member which is pressed against the developing roller to restrict the amount of toner to be fed, so that a layer of toner is formed at a fixed thickness and fed into a developing area in contact with the photosensitive member. Thus a static latent image is produced on the developing roller. In this process, a developing bias voltage Va is supplied to the developing roller, a restricting voltage Vb is supplied to the toner restricting member so as to fix the thickness of the toner layer, and a supply voltage Vc is supplied to the feed roller to control the supply of toner.

Abstract: A developing device has a development roller for carrying toner on a surface thereof, a toner supply roller for supplying the toner to the development roller, a flat spring which comes into contact with the development roller, charges the toner to be supplied to the development roller and applies the toner to the development roller while regulating the thickness of a layer of the toner. The flat spring has a plurality of flat-plate parts including a contact flat-plate part which comes into contact with the development roller, and a curved part which connects the flat-plate parts to each other. In this structure, by arbitrarily selecting dimensional parameters of the flat spring, it is possible to easily obtain various flat springs having different properties. Therefore, for example, the stress to the toner and the stress to the members can be easily reduced simultaneously with a design of the flat spring.

Abstract: A holographic scanner for scanning a surface with a light beam is provided. The holographic scanner includes a light source for emitting light used as the light beam, a front hologram for diffracting the light emitted from the light source to produce a first diffracted beam, a rotary hologram disk having a disk plane and rotatable around an axis thereof vertical to the disk plane, the rotary hologram disk including a plurality of scanning holograms arranged on the disk plane in a circumferential direction, the scanning holograms diffracting the first diffracted beam to produce a second diffracted beam, and a rear hologram for diffracting the second diffracted beam to produce a third diffracted beam, the third diffracted beam being used as the light beam for illuminating the scanning plane.

Abstract: A holographic scanner for scanning a surface with a light beam is provided. The holographic scanner includes a light source for emitting light used as the light beam, a front hologram for diffracting the light emitted from the light source to produce a first diffracted beam, a rotary hologram disk having a disk plane and rotatable around an axis thereof vertical to the disk plane, the rotary hologram disk including a plurality of scanning holograms arranged on the disk plane in a circumferential direction, the scanning holograms diffracting the first diffracted beam to produce a second diffracted beam, and a rear hologram for diffracting the second diffracted beam to produce a third diffracted beam, the third diffracted beam being used as the light beam for illuminating the scanning plane.

Abstract: A developing device for developing, by using a developer, a latent image formed on a surface of an image data forming member including a developer accommodating section for accommodating the developer; a first developer retaining member for receiving the developer from the developer accommodating section and transporting the developer; a second developer retaining member for receiving the developer from the first developer retaining member and making the developer adhere to the latent image formed on the image data forming member; a conductive member opposed to the second developer retaining member with an appropriate space interposed therebetween; a first voltage applying member for applying a voltage between the first developer retaining member and the second developer retaining member; a second voltage applying member for applying a voltage between the second developer retaining member and the surface of the image data forming member; and a third voltage applying member for applying a voltage between the s

Abstract: A hologram scanner includes a reproducing light source for generating a collimated reproducing light beam, a hologram disk being adapted to rotate, and a hologram disposed on the hologram disk for deflecting the reproducing light beam by diffraction so as to scan an image surface by the deflected reproducing light beam during a rotation of the hologram disk. The hologram has interference fringes recorded by a mutual interference of an object light of divergent spherical wave and a reference light of divergent spherical wave. The object light is generated by an object light source positioned at a first position apart from a hologram recording plane of the hologram disk, on which the hologram is to be recorded, by a first distance. The reference light is generated by a reference light source positioned at a second position apart from the hologram recording plane by a second distance.

Abstract: In an electrically excited transfer recording device which transfers an image or images formed in a recording film onto a recording chart, a recording head is comprised of a head base of resin having insulating properties and a plurality of electrode needles formed on the head base. During the printing, a resistance layer formed in the recording film is electrically charged by the electrode needles and ink contained in the recording film is fused upon generation of heat in the resistance layer to be transferred onto the recording chart.