Patent Application
20080019709
These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
Reference will now be made in detail to the present embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.
The PTB unit 420 feeds a printing medium along a predetermined transfer path of the image forming device, in order to transfer a developed latent image onto the printing medium. The printing medium may be paper, transparency sheets, etc. When a printing medium is picked up from a cassette (not shown), the PTB unit 420 develops an image onto the printing medium while the printing medium is moved along the predetermined transfer path, fixes the developed image, and discharges the printing medium. Referring to
The connection unit 490 connects the PTB unit 420 to the first controller 472 in conjunction with the installation of the PTB unit 420. Since the PTB unit 420 is preferably a replaceable part, the PTB unit 420 may preferably be designed to have a structure which allows a user to easily install and remove the PTB unit 420 after opening an outer cover 330 of an image forming device, as shown in
According to an embodiment of the present invention, the connection unit 490 connects the PTB unit 420 to the first controller 472 when the PTB unit device is installed into the image forming device, and disconnects the PTB unit 420 from the first controller 472 when the PTB unit 420 is removed from the image forming device.
Due to this characteristic of the connection unit 490 according to an embodiment of the present invention, the first controller 472 senses whether the PTB unit 420 is installed in the image forming device by using a feedback signal of electrical power applied to the PTB unit 420. If the PTB unit 420 is installed in the image forming device, the first controller 472 transmits electrical power of +5V to the PTB unit 420, and if the transmitted electrical power of +5V is then fed back to the first controller 472 via the connection unit 490, a feedback signal of +5V is input to the first controller 472. If the PTB unit 420 is not installed in the image forming device, the electrical power of +5V transmitted by the first controller 472 cannot be transmitted to the PTB unit 420, and thus the feedback signal of +5V cannot be fed back to the first controller 472 from the PTB unit 420.
In an embodiment of the PTB unit 420, the connection unit 490 is installed using a drawer connector, and the electrical power transmitted to the PTB unit 420 by the first controller 472 is then fed back to the first controller 472 using a harness pin attached to the drawer connector. In another embodiment of the PTB unit 420, the joint board 500 of the PTB unit 420 is installed using a printed circuit board (PCB). In this other embodiment, the electrical power transmitted to the PTB unit 420 by the first controller 472 is fed back to the first controller 472 using a detour pattern of the joint board 500. One skilled in the art would understand that there are other ways to install the PTB unit 420 besides these two above-described embodiments.
The connection unit 490 transfers electrical power transmitted by the first controller 472, along with control signals of the sensors 520, 530, 540 and 550, to the PTB unit 420, and transfers signals generated by the PTB unit 420, e.g., output signals which output results sensed by the sensors 520, 530, 540 and 550, back to the first controller 472. Thus, instead of sensing whether the PTB unit 420 is installed in the image forming device by using the feedback signal of electrical power applied to the PTB unit 420, the installation of the PTB unit 420 may instead be sensed according to whether signals outputted from the sensors 520, 530, 540 and 550 and the memory 510, each of which is preferably included in the PTB unit 420, are inputted to the first controller 472.
The cover switch 440 is a micro-switch that is turned on and off when the outer cover 330 is closed and opened, respectively. The first controller 472 transmits electrical power of +24V to the cover switch 440, wherein an output signal of the cover switch 440 is transmitted to the motor 402 included in the LSU 400. The output signal of the cover switch 440 is also fed back to the first controller 472. The first controller 472 receives the electrical power of +24V from the power supply unit 480 and applies the electrical power of +24V to the cover switch 440. If the outer cover 330 of the image forming device is closed, the cover switch 440 is in an “on state,” and thus, the output signal of the cover switch 440 is transmitted to the motor 402 included in the LSU 400 and then fed back to the first controller 472. If the outer cover 330 of the image forming device is open, the cover switch 440 is in an “off” state, and therefore, the electrical power of +24V is not fed back to the first controller 472.
Thus, the first controller 472 senses whether the outer cover 330 is open or closed using the feedback signal of +24V received from the cover switch 440. Specifically, if the electrical power of +24V transmitted to the cover switch 440 by the first controller 472 is fed back to the first controller 472 via the cover switch 440, the first controller 472 determines that the outer cover 330 is closed. On the other hand, if the electrical power of +24V transmitted to the cover switch 440 by the first controller 472 is not fed back to the first controller 472, the first controller 472 determines that the outer cover 330 is open.
The power supply unit 480 generates electrical power which is supplied to the PTB unit 420 and the LSU 400. The power supply unit 480 may preferably be implemented as a switch mode power supply (SMPS), but it is understood that other types of power supplies may be used instead of an SMPS. The SMPS 480 generates the electrical power of +24V to drive the motor 402 of the LSU 400, and also generates the electrical power of +5V to drive other electrical parts in the image forming device, such as the LD 404. Furthermore, the power supply unit 480 supplies the generated electrical power of +24V and +5V to the first controller 472, and in turn, the first controller 472 controls and transmits the electrical power supplied by the power supply unit 480 to the PTB unit 420 and the LSU 400.
The first controller 472 senses whether the PTB unit 420 is installed in the image forming device using the feedback signal (hereinafter referred to as a first signal) received from the connection unit 490 and senses the opening and closing of the outer cover 330 using the feedback signal (hereinafter referred to as a second signal) received from the cover switch 440. The first controller 472 controls the power supplied to the PTB unit 420 according to whether the PTB unit 420 is installed and whether the outer cover 330 is open or closed by using these first and second signals.
If the first controller 472 detects that both the first and second signals are high, the first controller 472 determines that the PTB unit 420 is installed in the image forming device and determines that the outer cover 330 is closed. In this case, the first controller 472 transmits the electrical power received from the power supply unit 480 to the LD 404 of the LSU 400. On the other hand, if the first controller 472 detects that either the first and/or second signal is low, the first controller 472 determines that the PTB unit 420 is not installed and/or the outer cover 330 is open. In this case, the first controller 472 cuts off the power supplied to the LD 404 of the LSU 400.
The first controller 472 outputs a ‘PTB_EXIST’ signal to indicate the existence of the PTB unit 420 within the image forming device, which is sensed using the first signal, and a ‘COVER_CLOSED’ signal to indicate whether the outer cover 330 is opened or closed, which is sensed using the second signal, to the second controller 474. In an embodiment of the present invention, the first controller 472 may be implemented as a micom controller. However, the first controller 472 is not limited to being a micom controller, and it will be understood by those of ordinary skill in the art that the first controller 472 may also be implemented using other methods.
The second controller 474 receives the ‘PTB_EXIST’ signal and the ‘COVER_CLOSED’ signal from the first controller 472 and turns on or off the first controller 472 according to the ‘PTB_EXIST’ signal and the ‘COVER_CLOSED’ signal. According to an embodiment of the present invention, the ‘PTB_EXIST’ signal is an “on” signal if the PTB unit 420 is installed, i.e., if the first signal is high, and is an “off” signal if the PTB unit 420 is not installed, i.e., if the first signal is low. In addition, the ‘COVER_CLOSED’ signal is an “on” signal if the outer cover 330 is closed, i.e., if the second signal is high, and is an “off” signal if the outer cover 330 is open, i.e., if the second signal is low.
If either the ‘PTB_EXIST’ signal or the ‘COVER_CLOSED’ signal is an “off” signal, the second controller 474 turns off the first controller 472. On the other hand, if both the ‘PTB_EXIST’ signal and the ‘COVER_CLOSED’ signal are “on” signals, the second controller 474 turns on the first controller 472. Thus, if either the ‘PTB_EXIST’ signal or the ‘COVER_CLOSED’ signal is an off signal, the second controller 474 cuts off all power supplied by the first controller 472 by turning off the first controller 472. By operating the first controller 472 and the second controller 474 in this fashion, since the electrical power supplied to the LSU 400, the electrical power supplied to the sensors 520, 530, 540 and 500, and the control signals supplied to the sensors 520, 530, 540 and 550 and the memory 510 included in the PTB unit 420, are cut off, problems generated by the sensors 520 through 550 and the memory 510 operating in an abnormal environment, such as a cover-open state, are prevented.
According to another embodiment of the present invention, the ‘COVER_CLOSED’ signal output from the first controller 472 is an “off signal” if either the first or second signals is low. In this case, the second controller 474 turns on or off the first controller 472 using only the ‘COVER_CLOSED’ signal.
When the second controller 474 turns on the first controller 472 using the ‘PTB_EXIST’ signal and the ‘COVER_CLOSED’ signal outputted from the first controller 472, the second controller 474 turns on the first controller 472 after a predetermined time has elapsed from when the second controller 474 receives the ‘PTB_EXIST’ signal and the ‘COVER_CLOSED’ signal. This predetermined time delay may be, for instance, after several hundred msec. By delaying turning on the first controller 472, the second controller 474 avoids instantaneously supplying electrical power to the PTB unit 420 and the LSU 400, in order to ensure that the image forming device operates in a stable fashion. More specifically, this predetermined time delay prevents the generation of instantaneous chattering noise immediately after the outer cover 330 is closed, and also prevents the generation of glitch noise at contact points of the connection unit 490, which are instantaneously contacted and released immediately after the PTB unit 420 is installed.
A simplified power control apparatus to control the sensors 520, 530, 540 and 550 and the memory 510 included in the PTB unit 420 will now be described with reference to
The sensors 520, 530, 540 and 550, the memory 510, and the joint board 500 are first described with reference to
In an embodiment of the present invention, the CR (color registration) sensors 520 and 530 are sensors which sense mismatch information between yellow, magenta, cyan, and black colors in a color image forming device. Additionally, the CR sensors 520 and 530 prevent an inter-color mismatch by detecting inter-color mismatch information through transferring a test pattern onto a PTB corresponding to each color during a self-diagnostic function process of the color image forming device performed before printing, and by compensating for scan timing and a margin of the LSU 400 in a main board.
The home detection optical sensor 540 is preferably, but not necessarily, a photo interrupt sensor to detect a home position of the PTB.
The CTD (conductivity temperature depth) sensor 550 is preferably, but not necessarily, a sensor to sense the depth of color in order to uniformly maintain the depth of color of the color image forming device. The CTD forms a test pattern on the PTB during a self-diagnostic function process similar to the process used by the CR sensors 520 and 530 to form a test pattern, and allows the main board to control color-depth compensation after sensing the depth of color.
The CRUM memory 510 is, preferably, but not necessarily, a semiconductor memory component to store life span information and ID information of the PTB. The life span information of the PTB is information about the number of printable sheets stored, since the PTB is a replaceable part. The ID information is information about a date of manufacture, customer vendors, a serial number, etc.
The joint board 500 preferably, but not-necessarily, includes the CRUM memory 510 and a joint disposed between the sensors 520, 530, 540 and 550 and the CRUM memory 510. The joint board 500 may be configured in ways other than the configuration illustrated in
Referring to
In order to reduce the number of connection lines of the connection unit 490, the first controller 472 according to an embodiment of the present invention includes a multiplexer to receive control signals for sensors and memories in the PTB unit 420, and to output a control signal of a selected unit according to a selection signal for one of the sensors and memories. The PTB unit 420 may further include a demultiplexer to receive the control signal outputted from the multiplexer and to transmit the control signal to the selected unit according to the selection signal. According to this design, since the connection unit 490 only transfers the control signal of the multiplexer and the selection signal to the PTB unit 420, the sensors and memories of the PTB unit 420 are controlled using a smaller number of connection lines than the number of connection lines used in a conventional image forming device.
Referring to
The connection unit 490 transfers the control signal corresponding to the selected sensor, i.e., an output signal of the multiplexer 600, along with the selection signal, to the PTB unit 420.
The PTB unit 420 receives the control signal corresponding to the selected sensor via an input terminal of a demultiplexer 610 and receives the selection signal via selection terminals of the demultiplexer 610. The demultiplexer 610 outputs the control signal corresponding to the selected sensor to the selected sensor among the plurality of sensors 510 through 550 in response to the selection signal.
For example, if a selection signal (a combination of S0, S1, and S2) to select the first CR sensor 520 is “0x000”, when the selection signal “0x000” is input to the selection terminal of the multiplexer 600, the multiplexer 600 outputs the first control signal to control the first CR sensor 520 from among the first through fifth control signals in response to the selection signal “0x000”.
Next, the connection unit 490 then transfers the first control signal, along with the selection signal “0x000,” outputted from the multiplexer 600 to the PTB unit 420.
The PTB unit 420 receives the first control signal via the input terminal of the demultiplexer 610 and the selection signal “0x000” via the selection terminals of the demultiplexer 610. The demultiplexer 610 outputs the first control signal to the first CR sensor 520 in response to the selection signal “0x000”.
As described above, if the PTB unit 420 includes a plurality of sensors and memory units, the present invention reduces the number of connection lines of the connection unit 490 by using the multiplexer 600 and the demultiplexer 610. Specifically, the PTB unit 420 using the multiplexer 600 and the demultiplexer 610 does not require preparing connection lines for individual control signals to control the plurality of sensors and memories and to transfer the control signals via the connection lines. This design simplifies a configuration of the connection unit 490 and provides a power control apparatus of an image forming device with reduced manufacturing costs and an efficient layout.
A power control method according to an embodiment of the present invention will now be described with reference to
The controller transmits electrical power of +5V to the PTB unit in operation 700 and feeds the transmitted electrical power back to in operation 710.
The controller senses whether the PTB unit is installed in the image forming device according to the feedback result in operation 720. If the PTB unit is installed in the image forming device, the electrical power transmitted to the PTB unit is fed back to the controller, and if the PTB unit is not installed in the image forming device, the electrical power transmitted to the PTB unit is not fed back to the controller. Thus, the controller senses whether the PTB unit is installed in the image forming device according to a feedback signal of the power transmitted to the PTB unit.
The controller senses the opening and closing of the cover in operation 730. For example, the controller senses the opening and closing of the cover using the cover switch 440 turned off and on in conjunction with the opening and closing of the cover, respectively, which is illustrated in
In operation 740, the controller cuts off power supplied to the PTB unit and the LSU according to the results sensed by the controller in operations 720 and 730. If the controller senses either that the PTB unit is not installed in the image forming device, or that the cover is open, the power supplied to the PTB unit and the LSU is cut off by turning off the controller in operation 740.
According to an embodiment of the power control method, in operations 700 through 730, the controller first senses whether the PTB unit is installed in the image forming device, and then senses whether the cover is open or closed. In other embodiments, the controller may sense whether the PTB unit is installed in the image forming device after sensing whether the cover is opened or closed, or the controller may simultaneously sense whether the PTB unit is installed in the image forming device and whether the cover is open or closed. In these embodiments, if the controller senses a power cut-off state for either the installation of the PTB unit or the cover, the power supplied to the PTB unit and the LSU is cut off.
As described above, according to aspects of the present invention, since a controller senses whether a PTB unit is installed into an image forming device according to a connection state of the PTB unit by using a simple method which implements a feedback signal corresponding to the electrical power supplied to the PTB unit, and since an LSU is controlled according to whether the PTB unit is installed, a power control apparatus and method of an image forming device is provided which has a simple configuration, reduced manufacturing costs, and a superior layout.
In addition, in order to prevent various kinds of sensors and memory units included in the PTB unit from operating incorrectly and/or operating out of order due to a mistake of a user when the image forming device abnormally operates due to the opening and closing of the outer cover, electrical power supplied to the various kinds of sensors and memory included in the PTB unit is instantaneously cut off according to whether the outer cover of the image forming device is open or closed. Furthermore, the electrical power is supplied back to the various sensors and memory units after a predetermined time has elapsed from when the electrical power is cut off, thus providing a power control apparatus and method of using the power control apparatus in an image forming device which controls electrical power supplied to the PTB unit and the LSU in a stable fashion.
Additionally, aspects of the present invention provide a power control apparatus with low manufacturing costs and a superior layout by simplifying a configuration to control the various kinds of sensors and memory units included in the PTB unit. Specifically, a multiplexer and a demultiplexer are respectively inserted into the first controller and the PTB unit, thereby reducing the number of connection lines needed in a connection unit.
Although a few of the embodiments of the present invention have been shown and described, it would be appreciated by those of skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-68090 | Jul 2006 | KR | national |
