摘要:
A screen printer effects a printing by moving a squeegee in contact with a screen to force a printing paste through a printing pattern formed on the screen. The squeegee is held by a squeegee head. The squeegee head includes a support member for supporting the squeegee in such a manner as to move the squeegee upward and downward, and at least one moving member which swingably supports the support member and is movable together with the support member. When the squeegee is to be exchanged, only the support member is angularly movable relative to the moving member so as to provide a sufficient space above the screen to facilitate the exchange of the squeegee.
摘要:
A large number of holes are formed in a two-layered porous film sandwiched between a lower substrate and an upper substrate and filled with a light transmitting liquid and fine particles. When a voltage is applied between an upper electrode and a lower electrode, migration of the fine particles, takes place based on electrophoresis. White color is displayed when the fine particles are located on an upper transparent porous film side and black color is displayed when the fine particles are located on a lower black porous film side. Color display is also possible by periodically repeating three primary colors of RGB in the lower layer porous film or arranging a color filter on the transparent upper substrate. Bubbles-containing fine particles or bubbles themselves may be employed in place of the fine particles.
摘要:
An exposure apparatus for image formation uses power control means provided to a laser driver for controlling exposure energy and accordingly forming an image. Specifically, exposure energy is varied depending on an isolated-dot pattern and an isolated-line pattern by changing the pulse height (drive power) of a drive pulse for each dot. Both of the isolated-line and isolated-dot patterns of a high resolution can thus be reproduced with a high image quality without increase of cost due to requirements for accuracy in processing and positioning of a lens and without decrease of life of a photoreceptor due to a decreased thickness of its photosensitive layer.
摘要:
In a digital electrophotographic imaging process in which a latent electrostatic image is written to a charged photoreceptor using an exposure beam diameter Ds larger than pixel pitch Dp and the image is visualized by development, an unsaturated region of photo-induced discharge characteristics of the photoreceptor is used for an image portion of isolated 1 line, and a saturated region of the photo-induced discharge characteristics of the photoreceptor or gamma characteristics of development is used for an image portion for n lines (n≧2).
摘要:
An object of the present invention is to prevent an electrical breakdown of a toner layer and an occurrence of overcurrent, thereby preventing quality of image from being degraded at the time of development, when development with one-component toner is conducted using a developing roller of low resistance. The resistance value Rd of a developing roller which carries and conveys one-component toner in a manner of coming into contact with a photoconductor which bears an electrostatic latent image, is defined as Rd=.rho.d.multidot.(Dd1/S1), wherein S1 (cm.sup.2) is an area in which the developing roller comes into contact with the static image bearing member via a toner layer, Dd1 (cm) is a layer thickness of a semiconductive layer which composes the developing roller, and .rho.d (.OMEGA..multidot.cm) is a volume resistivity thereof. The range of the resistance Rd is set as 10.sup.4 5.times.10.sup.7. By using the developing roller of low resistance, excellent development is realized and an electrical breakdown and an overcurrent can be avoided by the resistance value of the toner layer.
摘要:
A control unit of an image forming apparatus for controlling exposure energy includes a reference image storage unit storing a plurality of reference images, an image recognition unit comparing image information consisting of a plurality of pieces of pixel information with data stored in the reference image storage unit, an exposure energy density storage unit storing an exposure energy density for each reference image stored in the reference image storage unit, an exposure energy density determination unit based on data from the image recognition unit and data in the exposure energy density storage unit an exposure energy density to be applied to a dot position corresponding to each piece of the pixel information, and a laser drive driving a laser of an exposure unit based on data from the exposure energy density determination uni. Accordingly, the image forming apparatus can be provided which exhibits an excellent image reproducibility for images with various dot densities.
摘要:
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. Moreover, it is possible to improve the uniformity of the toner layer thickness in the axis direction of the development roller and the uniformity of charging of the toner.
摘要:
An oxidation-resistant silicon nitride material possessing a surface layer of a phase of closely packed crystals is produced by a procedure which comprises covering the surface of a silicon nitride substrate with a layer of an alkali metal compound, firing the coated substrate at a temperature of between 800.degree. C. and 1,300.degree. C., thereby forming an alkali metal-containing vitreous coating layer on the surface of the silicon nitride substrate, and thereafter removing the coating layer.
摘要:
A developing device and a blade of the developing device, includes a contact section which is in plane contact with a development roller, and an inclined section which extends from an end of the contact section so as to form a flare at an inflow section of a one-component developer between the blade and development roller. When a flare angle between the blade having the flare and a line tangent to the development roller is denoted by a tilt angle &thgr;, 30°≦&thgr;≦90°. Thus, if the flare angle at the inflow section of the one-component developer between the blade and development roller is optimized, even when the one-component developer deteriorates with time, for example, the flowability is changed with time, it is possible to provide a developing device and a blade of the developing device capable of forming a one-component developer layer with an extremely stable deposit of one-component developer. Moreover, it is possible to provide a blade which can increase the dimensional tolerance of the inclined section and can be produced easily at a low cost.
摘要:
An image forming apparatus has the following characteristics: the diameter of an exposure beam for exposing a latent image is not more than twice a minimum dot recording period p in peak intensity 1/e2, and the value of a spatial frequency characteristic function of a latent image defined by the thickness of a photoreceptor layer, the dielectric constant of the photoreceptor layer, the thickness of a developer layer, the dielectric constant of the developer layer and a spatial frequency &ohgr; defined as &ohgr;=&pgr;/p is at least 0.3. The image forming apparatus having such characteristics can reproduce an image of high resolution exceeding 600 to 1200 DPI with high fidelity.
摘要翻译:图像形成装置具有以下特征:用于曝光潜像的曝光光束的直径不大于峰值强度1 / e2的最小点记录周期p的两倍,并且潜在的空间频率特征函数的值 由感光体层的厚度,感光体层的介电常数,显影剂层的厚度,显影剂层的介电常数和定义为Ω= pi / p的空间频率Ω定义的图像为至少0.3。 具有这种特征的图像形成装置可以以高保真度再现超过600至1200DPI的高分辨率图像。