Abstract: To prevent irregular print density resulting from an uneven toner layer, a developer remover which may be a plurality of cylindrical members 31 formed like rollers, a net-like member, roller member and/or a contact member, are arranged in a manner to contact a sponge roller 22. When residual toner on the surface of a developing roller 21 is scraped off by the sponge roller 22, the developer remover pushes the toner away without allowing the toner to clot inside the sponge roller 22. Consequently, the sponge roller's performance to remove toner from itself to the developing roller 21 can be preserved for a long time.

Abstract: A toner container 40 includes a fresh toner chamber 46 and a waste toner chamber 47 separated by a partition wall 45. A width “a” of the interior of the fresh developer chamber 46 at an arbitrary vertical position VP along the partition wall 45 is substantially equal to or less than a corresponding width “b” at another position below the vertical position VP. The waste toner chamber 47 has a waste toner collection opening 55 through which a toner discharging mechanism 32 is inserted. A guide member 56 guides a discharging lid 57 for opening and closing the waste toner collection opening 55. The guide member 56 extends inwardly from the vicinity of an upper periphery of the waste toner collection opening 55, so that the toner discharging mechanism 32 that has entered in the waste toner chamber 47 is covered by the guide member 56 from above.

Abstract: A developing unit is disposed substantially directly under a toner chamber and receives toner through an opening formed in the toner chamber, and includes a developing roller, a supplying roller, and a developing blade. The developing roller supplies toner to an electrostatic latent image formed on an image bearing body. The supplying roller rotates in contact with the developing roller to supply the toner to the developing roller. The developing blade is in pressure contact with the developing roller to form a thin layer of toner on the developing roller. The developing blade is in contact with the developing roller at a first position spaced at least 5.84 mm from a second position at which the supplying roller is in contact with the developing roller. An agitating member may be added over the developing roller and supplying roller and between the first position and the second position.

Abstract: To prevent irregular print density resulting from an uneven toner layer, a plurality of cylindrical members 31 formed like rollers are arranged in a manner to contact the sponge roller 22. When the residual toner on the surface of the developing roller 21 is scraped off by the sponge roller 22, the cylindrical members 31 push the toner away without allowing the toner to clot inside the sponge roller 22. Consequently, the sponge roller's performance to remove toner from itself to the developing roller 21 can be preserved for a long time.

Abstract: A developing unit is disposed substantially directly under a toner chamber and receives toner through an opening formed in the toner chamber, and includes a developing roller, a supplying roller, and a developing blade. The developing roller supplies toner to an electrostatic latent image formed on an image bearing body. The supplying roller rotates in contact with the developing roller to supply the toner to the developing roller. The developing blade is in pressure contact with the developing roller to form a thin layer of toner on the developing roller. The developing blade is in contact with the developing roller at a first position spaced at least 5.84 mm from a second position at which the supplying roller is in contact with the developing roller. An agitating member may be added over the developing roller and supplying roller and between the first position and the second position.

Abstract: An echo canceller comprises an adaptive digital filter and a low frequency component suppresser. The canceller is used for two-wire full duplex digital data transmission system. The adaptive filter comprises a transversal filter with plural number of taps for generating an echo replica signal by adaptively estimating the time-varying transfer characteristics of an echo path in order to suppress the echo signal from the echo path. The low frequency component suppresser is installed in parallel with the adaptive filter to effectively increase the number of taps of the transversal filter, and to suppress the level of the low frequency component contained in a residual echo signal which is the difference between the echo signal and the echo replica signal at tail portion of the impulse response of the echo replica signal. Due to the low frequency component suppresser, the number of taps of transversal filter is considerably decreased and the arithmetic operation is greatly reduced.

Abstract: A frame pattern inserter inserts a frame pattern generated by a frame pattern generator periodically into a signal to be transmitted. An echo canceling circuit generates a pseudoecho from the signal to be transmitted with the frame pattern inserted therein and an error signal. A timing controller extracts from a received signal a timing signal to control the frame pattern generator, the frame pattern inserter, and the echo canceling circuit, and outputs a phase signal indicating whether jitter of the timing signal is generated as a leading phase shift or a lagging phase shift. A jitter echo canceling circuit generates a pseudojitter echo from the error signal and the phase signal. The timing controller controls the timing signal to cause the jitter to be generated immediately after the frame pattern is inserted into the signal to be transmitted.

Abstract: An echo canceller system includes a code converting circuit for converting binary serial data into two-bit units to generate a two-bit converter code. The bits of the converted code are added after each is amplified to a predetermined level, and the result of the addition is subjected to a DC offset circuit to generate a 2B1Q code. Part of the 2B1Q code, which is transmitted via a 2-wire transmission path, returns to the receiving side of the canceller system as an echo signal. The echo signal is canceled by at least one echo canceller, which can include an adaptive filter network and a subtracter unit.

Abstract: A DC termination circuit is provided for keeping a sealing current on a subscriber line during normal operation in order to prevent an oxidation of contacts in said line. The termination circuit is coupled across the line in response to the normal relatively high line voltage. In order to test the line, especially for its electrostatic capacitance, the line voltage is switched off and a relatively low voltage is applied through test equipment to the line. Responsive thereto, the termination circuit is removed from the line to terminate the sealing current.

Abstract: A FSK code with reduced high frequency content is generated. First through fourth waveforms are provided to a selector which selects one of the four waveforms in accordance with a control signal which, in turn, is generated in accordance with a state indication signal identifying the presently selected one of the four waveforms. A D/A converter converts the selected digital waveform data to an analog waveform signal. First and second of the digital waveform data represent +sin .theta. and -sin .theta., and third and fourth of the digital waveform data represent +f(.theta.) and -f(.theta., respectively, where ##EQU1## wherein 0.ltoreq..theta..ltoreq.2.pi. and a, b and c are nonzero coefficients.

Abstract: A magnetic transmission device using the edge-guided mode of propagation includes a magnetic dielectric slab having a conductor plate member mounted thereon adapted to be magnetized perpendicular to a ground plane on which the slab is placed. The conductor plate member is partially short-circuited to the ground plane.