초록 ▼

A communication system includes a network control facility (205), two downstream channels (212, 213), at least one remote interface unit (209, 210), and at least one communication device (201, 202) associated with each remote interface unit (RIU). Each RIU operates in one of two operating modes: a l

A communication system includes a network control facility (205), two downstream channels (212, 213), at least one remote interface unit (209, 210), and at least one communication device (201, 202) associated with each remote interface unit (RIU). Each RIU operates in one of two operating modes: a low power, standby mode and a high power, active mode. One downstream channel (212) is the primary downstream channel and is used by the network control facility to communicate user information and normal maintenance or control information to the RIU when the RIU is in the active mode. The other downstream channel (213) is the secondary downstream channel and is used by the network control facility to communicate special control information, such as a wake-up command, to the RIU when the RIU is in standby mode. The wake-up command instructs the RIU to transition from standby mode to active mode in order to receive user or control information over the primary downstream channel. Alternatively, the RIU may transition from standby mode to active mode on its own upon detecting a desire (e.g., off-hook signal) by the RIU's associated communication device to communicate in the system. The secondary downstream channel utilizes a substantially slower transmission speed (e.g., a lower order modulation) than does the primary downstream channel, thereby enabling the RIU to consume substantially less power when in standby mode than when in active mode, without adversely impacting the throughput rate of the primary downstream channel.

대표청구항 ▼

A communication system includes a network control facility (205), two downstream channels (212, 213), at least one remote interface unit (209, 210), and at least one communication device (201, 202) associated with each remote interface unit (RIU). Each RIU operates in one of two operating modes: a l

A communication system includes a network control facility (205), two downstream channels (212, 213), at least one remote interface unit (209, 210), and at least one communication device (201, 202) associated with each remote interface unit (RIU). Each RIU operates in one of two operating modes: a low power, standby mode and a high power, active mode. One downstream channel (212) is the primary downstream channel and is used by the network control facility to communicate user information and normal maintenance or control information to the RIU when the RIU is in the active mode. The other downstream channel (213) is the secondary downstream channel and is used by the network control facility to communicate special control information, such as a wake-up command, to the RIU when the RIU is in standby mode. The wake-up command instructs the RIU to transition from standby mode to active mode in order to receive user or control information over the primary downstream channel. Alternatively, the RIU may transition from standby mode to active mode on its own upon detecting a desire (e.g., off-hook signal) by the RIU's associated communication device to communicate in the system. The secondary downstream channel utilizes a substantially slower transmission speed (e.g., a lower order modulation) than does the primary downstream channel, thereby enabling the RIU to consume substantially less power when in standby mode than when in active mode, without adversely impacting the throughput rate of the primary downstream channel. ecording web roll; and (4) the inner edge part of the thermal transfer recording web roll is so constructed that the inner edge part can be clamped by the rotative driving members. positioned between said first and second optical devices for focusing said light; a movable sheet transfer belt contacting said photoconductive members, wherein the developing images are transferrable to an image forming medium, wherein said single mirror and each said light source lie in substantially the same plane, wherein a rotational speed R1 of the means for reflecting and scanning is a set predetermined value as described in the following equations: R1=R2×(n/m)×(M/N)×(D1/D2) (rpm) m>n≥1 (m, n:integer), wherein R1 (rpm) is the rotational speed of the means for reflecting and scanning in the single color mode, R2 (rpm) is a rotational speed of the means for reflecting and scanning in the multiple color mode, M (mm/s) is a rotational speed of the photoconductive means in the single color mode, N (mm/s) is a rotational speed of the photoconductive means in the multiple color mode, D1 (dpi) is a recording density in the single color mode, D2 (dpi) is a recording density in the multiple color mode, "n" is a maximum number of the light beams of light sources for yellow, magenta and cyan, and "m" is a maximum number of the light beams of the light source for black, and wherein a clock frequency F1 of the image forming apparatus is set based on the following equation: F1=F2×(n/m)×(M/N)×(D1/D2)2(MHZ), where F1, F2 is the clock frequency at the single color mode and the multiple color mode, respectively. 7. An image forming apparatus, comprising: an optical system in which a first light source selectably emits a plurality of image forming light beams based upon control signals and a second light source is emitting a single beam; a plurality of photoconductive devices for forming an electrostatic latent image by said optical system; a plurality of developing devices each arranged in connection with each of the photoconductive devices for supplying a developer to each of said photoconductive devices to develop latent images thereon; a movable sheet transfer belt contacting said photoconductive members, wherein the developed images are transferrable to an image forming medium; means for selecting image forming modes between a multiple color mode and a single color mode; means for selecting the number of light beams of a predetermined light source based upon the selected image forming mode; means for emitting the same number of light beams with said predetermined light source and the other light sources when the multiple color mode is selected; and means for reflecting and scanning light from each said first and second light source onto an image-forming surface, and said means for reflecting and scanning light comprising a single mirror common to each said light source and centrally positioned between said first and second focusing means for focusing said light, wherein said single mirror and each said light source lie in substantially the same plane, wherein a rotational speed R1 of the means for reflecting and scanning is a set predetermined value as described in the following equations: R1=R2×(n/m)×(M/N)×(D1/D2) (rpm) m>n≥1 (m, n:integer), wherein R1 (rpm) is the rotational speed of the means for reflecting and scanning in the single color mode, R2 (rpm) is a rotational speed of the means for reflecting and scanning in the multiple color mode, M (mm/s) is a rotational speed of the photoconductive means in the single color mode, N (mm/s) is a rotational speed of the photoconductive means in the multiple color mode, D1 (dpi) is a recording density in the single color mode, D2 (dpi) is a recording density in the multiple color mode, "n" is a maximum number of the light beams of light sources for yellow, magenta and cyan, and "m" is a maximum number of the light beams of the light source for black, and wherein a clock frequency F1 of the image forming apparatus is set based on the following equation: F1=F2×(n/m)×(M/N)×(D1/D2)2(MHZ), where F1, F2 is the clock frequency at the single color mode and the multiple color mode, respectively. 8. An image forming apparatus, comprising: an optical system in which a first light source selectably emits a plurality of image forming light beams based upon control signals and a second light source emits a lower number of image forming light beams than that of the first light source; a plurality of photoconductive devices for forming an electrostatic latent image by said optical system; a plurality of developing devices each arranged in connection with each of the photoconductive devices for supplying a developer to each of said photoconductive devices to develop latent images thereon; a movable intermediate transfer belt contacting said photoconductive members, wherein the developed images may be transferred to said transfer belt; a transfer member for contacting with a sheet, wherein the intermediate transferred images are transferrable to an image forming medium; means for selecting image forming modes between a multiple color mode and a single color mode; means for selecting the number of light beams of a predetermined light source based upon the selected image forming mode; means for emitting the same number of light beams with said predetermined light source and the other light sources when the multiple color mode is selected; and means for reflecting and scanning light from each said first and second light source onto an image-forming surface, and first and second focusing means for focusing said light; said means for reflecting and scanning light comprising a single mirror common to each said light source and centrally positioned between said first and second focusing means for focusing said light, wherein said single mirror and each said light source lie in substantially the same plane, wherein a rotational speed R1 of the means for reflecting and scanning is a set predetermined value as described in the following equations: R1=R2×(n/m)×(M/N)×(D1/D2) (rpm) m>n≥1 (m, n:integer), wherein R1 (rpm) is the rotational speed of the means for reflecting and scanning in the single color mode, R2 (rpm) is a rotational speed of the means for reflecting and scanning in the multiple color mode, M (mm/s) is a rotational speed of the photoconductive means in the single color mode, N (mm/s) is a rotational speed of the photoconductive means in the multiple color mode, D1 (dpi) is a recording density in the single color mode, D2 (dpi) is a recording density in the multiple color mode, "n" is a maximum number of the light beams of light sources for yellow, magenta and cyan, and "m" is a maximum number of the light beams of the light source for black, and wherein a clock frequency F1 of the image forming apparatus is set based on the following equation: F1=F2×(n/m)×(M/N)×(D1/D2)2(MHZ), where F1, F2 is the clock frequency at the single color mode and the multiple color mode, respectively. 9. An image forming apparatus, comprising: an optical system in which a first light source selectably emits a plurality of image forming light beams based upon control signals and a second light source emits a single beam; a plurality of photoconductive devices for forming an electrostatic latent image by said optical system; a plurality of developing devices each arranged in connection with each of the photoconductive devices for supplying a developer to each of said photoconductive devices to develop latent images thereon; a movable intermediate transfer belt contacting said photoconductive members, wherein the developed images are transferrable to said transfer belt; a transfer member for contacting with a sheet wherein the intermediate transferred images are transferrable to an image forming medium; means for selecting image forming modes between a multiple color mode and a single color mode; means for selecting the number of light beams of a predetermined light source based upon the selected image forming mode; means for emit ting the same number of light beams with said predetermined light source and the other light sources when the multiple color mode is selected; and means for reflecting and scanning light from each said first and second light source onto an image-forming surface, and first and second focusing means for focusing said light; said means for reflecting and scanning light comprising a single mirror common to each said light source and positioned between said first and second focusing means for focusing said light, wherein said single mirror and each said light source lie in substantially the same plane, wherein a rotational speed R1 of the means for reflecting and scanning is a set predetermined value as described in the following equations: R1=R2×(n/m)×(M/N)×(D1/D2) (rpm) m>n≥1 (m, n:integer), wherein R1 (rpm) is the rotational speed of the means for reflecting and scanning in the single color mode, R2 (rpm) is a rotational speed of the means for reflecting and scanning in the multiple color mode, M (mm/s) is a rotational speed of the photoconductive means in the single color mode, N (mm/s) is a rotational speed of the photoconductive means in the multiple color mode, D1 (dpi) is a recording density in the single color mode, D2 (dpi) is a recording density in the multiple color mode, "n" is a maximum number of the light beams of light sources for yellow, magenta and cyan, and "m" is a maximum number of the light beams of the light source for black, and wherein a clock frequency F1 of the image forming apparatus is set based on the following equation: F1=F2×(n/m)×(M/N)×(D1/D2)2(MHZ), where F1, F2 is the clock frequency at the single color mode and the multiple color mode, respectively. 10. An image forming apparatus, comprising: first light source means for selectably emitting a plurality of image forming light beams based upon control signals; second light source means for emitting a plurality of image forming light beams which is less than that of the first light source means; photoconductive means for forming an electrostatic latent image by said first light source means and said second light source means; developing means for developing the electrostatic latent image of said photoconductive means thereon; sheet transfer means for transferring an image forming medium to which the developed image is transferred; means for selecting image forming modes between a multiple color mode and a single color mode; means for selecting the number of light beams of a predetermined light source based upon the selected image forming mode; means for emitting the same number of light beams with said predetermined light source and the other light sources when the multiple color mode is selected; and means for reflecting and scanning light from each said first and second light source means onto an image-forming surface, and said means for reflecting and scanning light comprising a single mirror common to each said light source means and centrally positioned between said first and second means for focusing said light, wherein said single mirror and each said first and second light source means lie in substantially the same plane, wherein a rotational speed R1 of the means for reflecting and scanning is a set predetermined value as described in the following equations: R1=R2×(n/m)×(M/N)×(D1/D2) (rpm) m>n≥1 (m, n:integer), wherein R1 (rpm) is the rotational speed of the means for reflecting and scanning in the single color mode, R2 (rpm) is a rotational speed of the means for reflecting and scanning in the multiple color mode, M (mm/s) is a rotational speed of the photoconductive means in the single color mode, N (mm/s) is a rotational speed of the photoconductive means in the multiple color mode, D1 (dpi) is a recording density in the single color mode, D2 (dpi) is a recording density in the multiple color mode, "n" is a maximum number of the light beams of light sources for yellow, magenta and cyan,