摘要:
A corona charging device (52) has a plurality of discharge electrodes (2c) to which a high voltage from a voltage generating section 63 is applied. The discharge electrodes (2c) are within an electrically conductive case (2a) and separated from a photoreceptor (51) by an electrically biased grid (2d). The discharge current through the discharge electrodes (2c) required for a uniform charging of the photoreceptor is minimized, thereby minimizing the amount of generated ozone. This is achieved by keeping the ratios of the grid current I g , leakage current I c and the current I d flowing through the photoreceptor (51) within specific ranges.
摘要:
A blade (25) is pressed against a developing roller (21) for regulating the amount of toner which is deposited on a surface of the developing roller (21). The blade (25) is formed with a slant face (25a) at its tip end, to which the toner is transported along a direction of rotation of the developing roller (21). An angle of aperture θ at a toner inlet portion defined by the developing roller (21) and the slant face (25a) is set at 12.5° or more, the angle of aperture counting in an angle ψ of the slant face (25a), elastic deformation and radius (R) of the developing roller (21), and an angle α related to a nip width w on which the blade contacts with the developing roller (21). Such an angle of aperture θ provides a great allowance for a free length ℓ of the blade (25), thereby permitting the blade to maintain a constant toner mass for forming a uniform toner layer.
摘要:
An armored unit (12) includes a side cover (30) and a guide member (40). When sheet jam operation is carried out, a fixing unit (36) is pulled out with the armored unit (12), and then is pushed to the rear side. This operation unlocks the lock member (52) provided in the guide member (40), and a shoulder screw (51) moves in a guide hole (40a). Thus, the fixing unit (36) is moved from the pulled out position toward the rear side and toward the main body of image forming device to be shifted to a receding position. On this account, it is possible to provide an image forming device ensuring sufficient space for removing a jammed sheet by hand with a small opening space.
摘要:
An image reading apparatus includes a first reading element for receiving visible light in reflected light from a color document and reading image data corresponding to the visible light as electric signals, and a second reading element for receiving infrared light in reflected light from the color document and reading image data corresponding to the infrared light as electric signals. The image reading apparatus thus reads the image data not only from the visible light but also from the infrared light. Consequently, the image reading apparatus is capable of reading a special distinguishing pattern of copy-prohibited printed matter printed with special ink, such as infrared absorbing ink, as well as ordinary image data, and thereby preventing counterfeiting of copy-prohibited printed matter.
摘要:
A photosensitive sheet positioning device (35) used in an image forming apparatus provided with a photosensitive sheet wound in a roll, a leader sheet attached to the forefront edge of the photosensitive sheet, forwarding holes formed in a line on the sides of the leader sheet, and forwarding pins mounted and protruding on the outer circumference of a roller, whereon the forwarding holes are successively fitted, and that control the forwarding direction of the photosensitive sheet, comprises fastening holes (46) formed on the forefront portion of the leader sheet, and fastening pins (47) that restrain the motion of the leader sheet and that may be inserted in and removed from the fastening holes freely. Accordingly, in the present device, the forwarding holes may be fitted on the forwarding pins easily, rapidly and without being fitted in a shifted manner.
摘要:
A charging device is designed in the following manner. Firstly, an optimization of the shape and size of an MC case is performed based on a film thickness and process speed of a photoreceptor (S1). Then, optimization of grid conditions (S2), saw-tooth conditions (S3), a distribution ratio of discharge current (S4) and a grid voltage (S5) are performed respectively, and a minimization of the discharge current is performed (S6). Lastly, surrounding conditions are taken into consideration (S7). The order of performing the processes in S1~S6 is not specified. By designing the charging device so as to have at least one feature obtained by the processes in S2-S7, a stable discharging operation, a uniform charging operation on the surface of the photoreceptor, reduction in amount of ozone generated when discharging, and reduced size and cost of the charging device can be achieved, and the charging device can be designed effectively in a short period of time.