WO2021183243A1

WO2021183243A1 - Image formation using multiple application specific integrated circuits

Info

Publication number: WO2021183243A1
Application number: PCT/US2021/017034
Authority: WO
Inventors: Youn Jae Kim; Jin Kyu Park; Si Joong Jang
Original assignee: Hewlett-Packard Development Company, L.P.
Priority date: 2020-03-11
Filing date: 2021-02-08
Publication date: 2021-09-16
Also published as: KR20210114776A

Abstract

An image forming apparatus includes a communication device to receive printing data, a printing engine to form an image using laser scanning units (LSUs), and a processor to control the printing engine to print the printing data. A sub application specific integrated circuit (ASIC) performs beam control for at least one LSU among the LSUs and a main ASIC performs beam control for a plurality of LSUs other than the at least one LSU among the LSUs and performs motor control for the LSUs.

Description

IMAGE FORMATION USING MULTIPLE APPLICATION SPECIFIC INTEGRATED CIRCUITS

BACKGROUND

[01] An image forming apparatus may include an apparatus that performs generation, printing, reception, transmission, and the like, of image data. An example of the image forming apparatus may include a printer, a scanner, a copier, a facsimile, a multi-function printer in which functions of the printer, the scanner, the copier, the facsimile are complexly implemented, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS [02] FIG. 1 is a block diagram schematically illustrating a configuration of an image forming apparatus according to an example;

[03] FIG. 2 is a block diagram schematically illustrating a configuration of an image forming apparatus according to an example;

[04] FIG. 3 is a view illustrating a detailed configuration of a laser scanning unit (LSU) of FIG. 1 ;

[05] FIG. 4 is a view illustrating a detailed configuration of a printing engine of FIG. 1 ;

[06] FIG. 5 is a view for describing an operation of multiple application specific integrated circuits (ASICs) according to an example; [07] FIG. 6 is a sequence diagram for describing operations of a main processor and a sub processor of FIG. 5;

[08] FIG. 7 is a view for describing an operation of multiple ASICs according to an example; and

[09] FIG. 8 is a flowchart illustrating an image forming method according to an example.

DETAILED DESCRIPTION

[10] Hereinafter, various examples will be described in detail with reference to the drawings. Example to be described later may be modified into several different forms.

[11] Meanwhile, when any component is referred to as being “connected to” another component in the specification, it means that any component and another component are “directly connected to” each other or are “connected to” each other with the other component interposed therebetween. In addition, when any component is referred to as “including” another component, it means the inclusion of other components rather than the exclusion of other components, unless explicitly described to the contrary.

[12] In the specification, an “image forming job” may refer to various jobs (for example, printing, scanning, or faxing) related to an image, such as forming of the image, generating/storing/transmitting of an image file, or the like, and a “job” may refer to the image forming job, as well as include some or all of a series of processes for performing the image forming job.

[13] In addition, an “image forming apparatus” may refer to an apparatus that prints printing data generated in a terminal apparatus such as a computer on a recording paper. An example of such an image forming apparatus may include a copier, a printer, a facsimile, a multi-function printer (MFP) in which functions of the copier, the printer, and the facsimile are complexly implemented through one apparatus, or the like.

[14] FIG. 1 is a block diagram schematically illustrating a configuration of an image forming apparatus according to an example.

[15] Referring to FIG. 1 , an image forming apparatus 100 may include a communication device 110, a printing engine 120, and a processor 130. [16] The communication device 110 may be formed in order to connect the image forming apparatus 100 to an external apparatus (not illustrated), and may be connected to the external apparatus through a local area network (LAN) and the Internet network or be connected to the external apparatus through a universe serial bus (USB) port or through a wireless communication port (for example, via wireless fidelity (WiFi), 802.11 a/b/g/n, near field communication (NFC), or Bluetooth). Such a communication device 100 may also be referred to as a transceiver.

[17] The communication device 110 may receive printing data. The printing data may include information on a printing option set in the printing data, and one of the printing options may be a gloss processing option. Here, the gloss processing option is an option for performing gloss processing on a printing paper or printing medium.

[18] The printing engine 120 may form an image on the printing paper using multiple laser scanning units (LSUs) 200. For example, the printing engine 120 may include multiple organic photoconductor (OPC) drums capable of developing a cyan toner, a magenta toner, a yellow toner, a black toner, and a clear toner and the multiple LSUs 200 forming electrostatic latent images on each of the OPC drums. A detailed configuration of the LSU will be described later with reference to FIG. 3, and a detailed configuration of the printing engine 120 will be described later with reference to FIG. 4.

[19] Here, the clear toner is a toner in which a pigment indicating a color is omitted from a general toner, and may also be referred to as a transparent toner. Meanwhile, five toner colors including a clear color have been mentioned hereinabove, but this is an example, and other colors other than the color combination described above may be used.

[20] The printing engine 120 may perform gloss processing on the printing paper on which the image is formed. Here, the gloss processing is processing for giving gloss to an output through heating, cooling, and separation processes for the printing paper on which the image is formed. To this end, the printing engine 120 may include a gloss device which performs the gloss processing on the printing paper for which fixing processing is completed. [21] The processor 130 controls a general operation of the image forming apparatus 100. For example, the processor 130 may generally control an operation of the image forming apparatus 100 by executing at least one pre stored instruction. Such a processor 130 may be implemented by a central processing unit (CPU), an application specific integrated circuit (ASIC), or the like.

[22] When the printing data is received, the processor 130 may perform processing such as parsing on the received printing data to generate binary data, and control the printing engine 120 to print the generated binary data.

[23] In this case, the processor 130 may determine whether or not the gloss processing option is set. When the gloss processing option is not set as a result of the determination, the processor 130 may generate binary data for each of four colors C, M, Y, and K, and perform a printing job using a main ASIC 300. Here, the main ASIC 300 may be an ASIC for 4-color LSU control. A detailed operation of the main ASIC 300 will be described later with reference to FIG. 5.

[24] On the other hand, when the gloss processing option is set, the processor 130 may generate binary data for each of five colors C, M, Y, K, and a clear color, and perform a printing job using the main ASIC 300 and a sub ASIC 400. Here, the sub ASIC 400 may be an ASIC for single-color LSU control. A detailed configuration and operation of the sub ASIC 400 will be described later with reference to FIG. 5.

[25] Meanwhile, simple components of the image forming apparatus are illustrated and described hereinabove, but various components may be further included in the image forming apparatus according to the examples described herein. Various example components which may be further included in the image forming apparatus will be described below with reference to FIG. 2.

[26] FIG. 2 is a block diagram schematically illustrating a configuration of an image forming apparatus according to an example.

[27] Referring to FIG. 2, the image forming apparatus 100 according to an example of the disclosure may include the communication device 110, the printing engine 120, the processor 130, a memory 140, a display 150 and an input device 160. [28] The communication device 110, the printing engine 120, and the processor 130 perform the same functions as those of the components of FIG. 1 , and an overlapping description is thus omitted.

[29] The memory 140 may store at least one instruction regarding the image forming apparatus 100. For example, various programs (or software) for operating the image forming apparatus 100 according to various examples of the disclosure may be stored in the memory 140.

[30] The memory 140 may store printing data. For example, the memory 140 may store the printing data received from the communication device 110 described above. In addition, the memory 140 may temporarily store multiple image data generated by the processor 130.

[31] Such a memory 140 may be implemented by a storage medium in the image forming apparatus 100, as well as by an external storage medium, a removable disk including a USB memory, a web server through a network, or the like.

[32] The display 150 may display a user interface window for receiving a user’s selection for a function supported by the image forming apparatus 100. For example, the display 150 may display a user interface window for receiving a user’s selection for various functions provided by the image forming apparatus 100. Such a display 150 may be a monitor such as a liquid crystal display (LCD), a cathode ray tube (CRT), or organic light emitting diodes (OLED), and may be implemented by a touch screen capable of simultaneously performing a function of the input device 160.

[33] The display 150 may display a user interface window for receiving a user’s selection for the printing job and a setting for a printing option to be applied to the selected printing job.

[34] The input device 160 may receive a function selection and a control command for the function, input from a user. Here, the function may include a printing function, a copying function, a scanning function, and a fax transmission function.

[35] In addition, the input device 160 may receive a user’s selection for whether or not to apply a gloss processing function. For example, such a gloss processing function may be selected in a case where color printing (or photo printing) is selected.

[36] As described above, in the image forming apparatus 100 according to the disclosure, a combination of verified ASICs may be used, and it is thus possible to reduce a time and a cost as compared with a case of designing new ASICs. In addition, ASICs whose qualities have been already confirmed are used, and it is thus possible to immediately apply the image forming apparatus 100 to a product without generating degradation in an image quality.

[37] Meanwhile, in illustrating and describing FIGS. 1 and 2, it has been illustrated and described that the main ASIC and the sub ASIC are components of the processor, but the main ASIC and the sub ASIC may also be components of the printing engine.

[38] In addition, in illustrating and describing FIGS. 1 and 2, it has been illustrated and described to use two ASICs, but it is also possible to use three or more ASICs. In this case, motors for each of the LSUs may be simultaneously controlled by operating the main ASIC, which is one of the multiple ASICs.

[39] FIG. 3 is a view illustrating a detailed configuration of the LSU of FIG. 1 . Hereinafter, in order to facilitate a description, a description will be provided based on an LSU for a mono channel.

[40] Referring to FIG. 3, the LSU 200 may include a light source 201 , lenses 202, 203, and 207, a polygon mirror 204, a reflection mirror 205, and a beam detection sensor 206.

[41] The light source 201 includes a light source generating and outputting a light beam. A semiconductor diode may be used as the light source.

[42] The lenses 202, 203, and 207 focus the light beam output to the light source 201 to allow an image to be accurately formed on an OPC drum 121 or the beam detection sensor 206.

[43] The polygon mirror 204 may deflect the beam output from the light source toward the OPC drum 121 using multiple reflection surfaces. For example, the beam output from the light source device 201 is reflected along a constant scanning path by the reflection surfaces of the polygon mirror 204 that rotates. Here, the scanning path refers to a path through which the beam output from the light source passes.

[44] Such a polygon mirror 204 may include square reflection surfaces having an angle of 90°, and may include a motor to rotate at a constant speed.

[45] The reflection mirror 205 may reflect the beam reflected by the polygon mirror 204 at a predetermined angle toward the beam detection sensor 206.

[46] The beam detection sensor 206 may receive one beam output from the light source device 201 and reflected in a rotation process of the polygon mirror and output a beam detection signal. For example, in a case where the beam detection sensor 206 is disposed at a predetermined position and the beam output from the light source is reflected at a certain angle of the reflection mirror 205, the beam detection sensor 206 may detect the reflected beam and output a beam detection signal.

[47] There is a section in which an image is formed by the beam scanned to the OPC drum 121 , that is, an effective scanning width. A horizontal synchronization signal may be used in order to constantly form the effective scan width. Here, the horizontal synchronization signal is a signal generated on the basis of the beam detection signal generated by the beam detect sensor 206 described above.

[48] Meanwhile, in a case where the LSUs includes multiple light sources, the LSUs may generate multiple horizontal synchronization signals corresponding to each of the multiple light sources. In addition, the LSUs may group the multiple light sources into several groups and generate horizontal synchronization signals for each group. In each group, each of polygon mirrors of LSUs may be rotated by one motor.

[49] For example, in a case where five colors are divided into a first group (clear color) and a second group (C/M/Y/K), an LSU corresponding to the clear toner may be controlled by one motor, and multiple LSUs corresponding to C/M/Y/K toners may be controlled by one motor.

[50] FIG. 4 is a view illustrating a detailed configuration of the printing engine of FIG. 1.

[51] Referring to FIG. 4, the printing engine may include multiple OPC drums 121-1 , 121-2, 121-3, 121-4, and 121-5 and multiple developers 124-1 , 124-2, 124-3, 124-4, and 124-5.

[52] Here, a first OPC drum 121-1 and a first developer 124-1 are devices that develop a clear toner. The first OPC drum 121-1 may have an electrostatic latent image formed by a first LSU.

[53] In addition, a second OPC drum 121-2 and a second developer 124-2 are devices that develop a black toner. The second OPC drum 121-2 may have an electrostatic latent image formed by a second LSU.

[54] In addition, a third OPC drum 121-3 and a third developer 124-3 are devices that develop a yellow toner. The third OPC drum 121-3 may have an electrostatic latent image formed by the second LSU.

[55] In addition, a fourth OPC drum 121-4 and a fourth developer 124-4 are devices that develop a magenta toner. The fourth OPC drum 121-4 may have an electrostatic latent image formed by the second LSU.

[56] In addition, a fifth OPC drum 121-5 and a fifth developer 124-5 are devices that develop a cyan toner. The fifth OPC drum 121-5 may have an electrostatic latent image formed by the second LSU.

[57] As described above, an image developed on an intermediate transfer belt by the multiple OPC drums and the multiple developers as described above may be transferred to the printing paper through a transfer machine 125.

[58] Meanwhile, each of the five OPC drums described above forms an image at a correct point in time in order for the purpose of color registration. However, since a general ASIC supports one channel or four channels, the development of an ASIC supporting five channels has been demanded in order to simultaneously control the five channels (that is, five colors).

[59] However, since the development of a new ASIC takes a lot of time and effort, the disclosure uses a combination of an existing 1 -channel ASIC and 4- channel ASIC without developing a new ASIC. This will be described in detail below with reference to FIG. 5.

[60] FIG. 5 is a view for describing an operation example of multiple application ASICs according to an example. Hereinafter, in order to facilitate a description, a description will be provided on the assumption that the image forming apparatus uses five color toners and the five OPC drums use a 4- channel LSU and a 1 -channel LSU.

[61] Referring to FIG. 5, the printing engine includes a 4-channel LSU 200-1 and a 1 -channel LSU 200-2.

[62] The 4-channel LSU 200-1 may form electrostatic latent images for each of four OPC drums (for example, C/M/Y/K). In the 4-channel LSU 200-1 , four polygon mirrors may be simultaneously driven by one motor.

[63] The 1 -channel LSU 200-2 may form an electrostatic latent image for one OPC drum (for example, clear).

[64] The processor may include the main ASIC 300 and the sub ASIC 400.

[65] The main ASIC 300 may include a video controller 310, a PSYNC generator 320, and an LSU controller 330.

[66] The LSU controller 330 may perform motor control for the 4-channel LSU 200-1. For example, when an LSU operation is performed, the LSU controller 330 provides control signals LSU_MTR_CLK0 and LSU_MTR_EN0 for allowing a motor of the 4-channel LSU 200-1 to be driven at a constant speed to the 4- channel LSU 200-1.

[67] In addition, when a signal LSU_LREADY0 for informing the LSU controller 330 that the motor is driven at a constant speed is received from the 4-channel LSU 200-1 , the LSU controller 330 may control the motor so that a first horizontal synchronization signal HSYNC [0] generated by the 4-channel LSU 200-1 has a preset frequency. To this end, the LSU controller 330 may receive the first horizontal synchronization signal from the 4-channel LSU 200-1 .

[68] In addition, the LSU controller 330 may perform motor control for the 1- channel LSU 200-2. For example, when the first horizontal synchronization signal is stably output, the LSU controller 330 provides control signals LSU_MTR_CLK1 and LSU_MTR_EN1 for allowing a motor of the 1-channel LSU 200-2 to be driven at a constant speed to the 1 -channel LSU 200-2.

[69] In addition, when a signal LSU_LREADY1 for informing the LSU controller 330 that the motor is driven at a constant speed is received from the 1 -channel LSU 200-2, the LSU controller 330 may control the motor so that a second horizontal synchronization signal HSYNC_4 received from the 1 -channel LSU 200-2 has a preset frequency. Meanwhile, control of a video signal for generating the second horizontal synchronization signal may be performed in the sub ASIC 400.

[70] In addition, the LSU controller 330 may control two motors so that the second horizontal synchronization signal received from the 1 -channel LSU 200- 2 and the first horizontal synchronization signal received from the 4-channel LSU 200-1 have a preset time difference (or phase difference) therebetween, in consideration of positions of the LSUs. For example, the LSU controller 330 may control a motor speed of the 4-channel LSU 200-2 to allow the horizontal synchronization signals to have the preset time difference therebetween.

[71] To this end, the LSU controller 330 may receive the second horizontal synchronization signal from the 1 -channel LSU 200-2. Here, the second horizontal synchronization signal may have the same frequency as that of the first horizontal synchronization signal.

[72] The PSYNC generator 320 may generate a page synchronization signal PSYNC. For example, when the two horizontal synchronization signals received from the 1 -channel LSU 200-2 and the 4-channel LSU 200-1 has a preset speed difference therebetween, the PSYNC generator 320 may generate the page synchronization signal PSYNC. The page synchronization signal is a signal for informing the sub ASIC 400 of a start time of a page.

[73] In addition, the PSYNC generator 320 may provide the generated page synchronization signal to the sub ASIC 400.

[74] When printing data is received, the video controller 310 may generate multiple image data corresponding to the received printing data. In addition, the video controller 310 may provide image data (for example, a binary image for the clear toner) to be used in the 1 -channel LSU 200-2 among the multiple image data to the sub ASIC 400. At this time, the image data may be transmitted in various communication manners such as a USB, a general purpose output (GPO), Universal Asynchronous Transmitter (URT), Ethernet, PCI express.

[75] In addition, the video controller 310 may perform beam control for the 4- channel LSU 200-1. For example, when the two LSUs 200-1 and 200-2 are synchronized with each other as described above, the video controller 310 may determine a transmission point in time of video signals on the basis of the first horizontal synchronization signal and the page synchronization signal, and provide the video signals VDO-O, VDO-1 , VDO-2, and VDO-3 to the 4-channel LSU 200-1 at the determined transmission point in time. Here, the video signal is a signal supplied to the light source device of the LSU, and is a signal including image information in units of lines among the image data.

[76] The sub ASIC 400 may include a video controller 410 and an LSU controller 420.

[77] The LSU controller 420 may monitor a motor of the 1 -channel LSU 200-2. For example, when control signals LSU_MTR_CLK1 and LSU_MTR_EN1 for drive to the 1 -channel LSU 200-2 from the main ASIC 300 are provided to the motor of the 1 -channel LSU 200-2, the LSU controller 420 may confirm whether or not a signal LSU_LREADY1 for informing the LSU controller 420 that the motor is driven at a constant speed is received from the 1 -channel LSU 200-2.

[78] When the signal for informing the LSU controller 420 that the motor is driven at a constant speed is received, the LSU controller 420 may control a video signal used in the 1 -channel LSU 200-2 to allow the second horizontal synchronization signal HSYNC_4 to be generated.

[79] The video controller 410 may perform beam control for the 1 -channel LSU 200-2. For example, when the page synchronization signal is received from the main ASIC 300, the video controller 410 determines a transmission point in time of a video signal on the basis of the second horizontal synchronization signal and the page synchronization signal, and transmit a video signal VDO-4 corresponding to image data received from the main ASIC 300 to the 1 -channel LSU 200-2 at the determined point in time.

[80] Meanwhile, the video controller 410 may generate the video signal using the image data received from the main ASIC 300 as it is or may generate the video signal by perform additional processing on the image data.

[81] As described above, in the disclosure, one ASIC controls the motors of each of the two LSUs 200-1 and 200-2 in common, and it is thus possible to prevent deterioration in quality that may occur due to a difference in a speed between the two motors. [82] Meanwhile, in illustrating and describing FIG. 5, a system capable of controlling five LSUs using the 4-channel ASIC and the 1 -channel ASIC has been implemented, but the 4-channel ASIC and the 1 -channel ASIC may be variously combined with each other, in addition to the example described above. For example, two 4-channel ASICs may be used to control one channel and 4 channels, respectively, or control two channels and three channels, respectively.

[83] In addition, it has been illustrated and described that the five LSUs are divided into one LSU and four LSUs, but the five LSUs may be divided into two LSUs and three LSUs, for example.

[84] FIG. 6 is a sequence diagram for describing operations of the main processor and the sub processor of FIG. 5.

[85] Referring to FIG. 6, when the printing data is received (S605), the main ASIC may generate and provide image data to be used by the sub ASIC (S610). Correspondingly, the sub ASIC may receive the image data (S655).

[86] Then, the main ASIC may operate the motor of the first LSU (an LSU controlled by the main ASIC) and control a video signal for synchronization to allow the first horizontal synchronization signal that is stable to be generated (S615).

[87] Then, the main ASIC may operate the motor of the second LSU (an LSU controlled by the sub ASIC) (S620).

[88] When a speed of the motor of the second LSU becomes a constant speed (S625 and S660), the sub ASIC may control a video signal for synchronization (S665) to allow the second horizontal synchronization signal to be generated.

[89] Therefore, when the second horizontal synchronization signal is stabilized, the main ASIC may control the motor of the second LSU such that the two horizontal synchronization signals have a preset time difference therebetween (S630 and S650). Such control may be continuously performed while printing is performed below. In the illustrated example, it has been described that the second LSU is controlled to allow the two synchronization signals to have the preset time difference therebetween, but as another example the first LSU may be controlled to allow the two synchronization signals to have the preset time difference therebetween.

[90] When the two horizontal synchronization signals have the preset time difference therebetween according to such an operation, it is determined that the printing is possible (S635), and the main ASIC may generate the page synchronization signal PSYNC and provide the page synchronization signal PSYNC to the sub ASIC (S640).

[91] Then, the main ASIC may determine a start point in time when the video signal is to be transmitted according to the generated page synchronization signal and the first horizontal synchronization signal and provide the video signal to the LSU at the determined start point in time to perform the beam control (that is, printing) (S645).

[92] In addition, when the page synchronization signal is received (S670), the sub ASIC may determine a start point in time when the video signal is to be transmitted according to the provided page synchronization signal and the second horizontal synchronization signal and provide the video signal to the second LSU at the determined start point in time to perform the beam control (that is, printing) (S675).

[93] FIG. 7 is a view for describing an operation example of multiple ASICs according to a second example. For example, FIG. 7 will be described on the assumption that the five OPC drums use a 3-channel LSU and a 2-channel LSU.

[94] Referring to FIG. 7, the printing engine includes a 3-channel LSU 200-3 and a 2-channel LSU 200-4.

[95] The 3-channel LSU 200-3 may form electrostatic latent images for each of three OPC drums (for example, C/M/Y).

[96] The 2-channel LSU 200-4 may form electrostatic latent images for each of two OPC drums (for example, K/clear).

[97] A main ASIC 300’ may perform motor control for the 3-channel LSU 200- 3 and the 2-channel LSU 200-4. Such a main ASIC 300’ may include a video controller 310, a PSYNC generator 320, and an LSU controller 330. Operations of each of the video controller 310, the PSYNC generator 320, and the LSU controller 330 are the same as those of the components of FIG. 5, and an overlapping description is thus omitted.

[98] The main ASIC 300’ may perform beam control for the 3-channel LSU 200-3. In addition, the main ASIC 300’ may also perform beam control for some of the beams of the 2-channel LSU 200-4.

[99] The sub ASIC 400’ may perform beam control for some of the beams of the 2-channel LSU 200-4. A detailed configuration and operation of the sub ASIC 400’ are the same as those of FIG. 5, and an overlapping description is thus omitted.

[100] As such, even though the number of channels supported by the ASICs and the number of channels of the LSUs do not correspond to each other in a one-to-one manner, multiple ASICs and multiple LSUs may be variously combined with each other.

[101] FIG. 8 is a flowchart illustrating an image forming method according to an example.

[102] Referring to FIG. 8, printing data may be received (S810). Various print options may be set in such printing data.

[103] Multiple video signals may be generated using the printing data (S820). For example, when a black and white option is set in the printing data, image data for black and white may be generated, and a video signal corresponding to the generated image data may be generated. In addition, when a color option is set in the printing data, image data for each of the four colors (C/M/Y/K) may be generated, and four video signals corresponding to each image data may be generated. In addition, when a gloss option is set in the printing data, image data for each of the five colors (Clear and C/M/Y/K) may be generated, and five video signals corresponding to each image data may be generated.

[104] Motor control for the multiple LSUs may be performed using one of the multiple ASICs (S830). For example, the motor control may be performed so that the first horizontal synchronization signal corresponding to at least one of the multiple LSUs and the second horizontal synchronization signal corresponding to the others of the multiple LSUs have a preset time difference therebetween.

[105] In addition, beam control for each of the multiple LSUs may be performed using the generated multiple video signals and the multiple ASICs (S840).

[106] Therefore, in the image forming method according to the example, a combination of verified ASICs may be used, and it is thus possible to reduce a time and a cost as compared with a case of designing new ASICs. In addition, ASICs whose qualities have been already confirmed are used, and it is thus possible to immediately apply the image forming apparatus 100 to a product without generating degradation in an image quality.

[107] In addition, the image forming method as described above may be implemented by at least one execution program for executing the image forming method as described above, and such an execution program may be stored and provided in a non-transitory computer readable medium.

[108] Although examples of the disclosure have been illustrated and described hereinabove, the disclosure is not limited to the examples described above, but may be variously modified by those skilled in the art to which the disclosure pertains without departing from the spirit and scope of the disclosure claimed in the claims. These modifications are to fall within the scope of the disclosure.

Claims

CLAIMS:

1. An image forming apparatus, comprising: a communication device to receive printing data; a printing engine to form an image using laser scanning units (LSUs); a processor to control the printing engine to print the printing data; a sub application specific integrated circuit (ASIC) to perform beam control for at least one LSU among the LSUs; and a main ASIC to perform beam control for a plurality of LSUs other than the at least one LSU among the LSUs and to perform motor control for the LSUs.

2. The image forming apparatus as claimed in claim 1 , wherein the main ASIC is to control the LSUs so that a second horizontal synchronization signal output from the at least one LSU and a first horizontal synchronization signal output from plurality of LSUs have a same frequency.

3. The image forming apparatus as claimed in claim 2, wherein the main ASIC is to control the LSUs so that the first horizontal synchronization signal and the second horizontal synchronization signal have a preset time difference therebetween.

4. The image forming apparatus as claimed in claim 2, wherein the main ASIC is to generate a page synchronization signal and is to provide the page synchronization signal to the sub ASIC, when the first horizontal synchronization signal and the second horizontal synchronization signal are stabilized.

5. The image forming apparatus as claimed in claim 4, wherein the sub ASIC is to perform the beam control for the at least one LSU based on the second horizontal synchronization signal and the page synchronization signal when the page synchronization signal is received from the main ASIC.

6. The image forming apparatus as claimed in claim 4, wherein the main ASIC is to perform beam control for each of the plurality of LSUs based on the first horizontal synchronization signal and the page synchronization signal.

7. The image forming apparatus as claimed in claim 1 , wherein the main ASIC is to transmit image data among a plurality of image data from the printing data to the sub ASIC, for the at least one LSU.

8. The image forming apparatus as claimed in claim 1 , wherein the processor includes the sub ASIC and the main ASIC, and the processor is to perform a printing job without using the sub ASIC when a gloss processing option is not included in the printing data, and is to perform a printing job using the sub ASIC and the main ASIC when the gloss processing option is included in the printing data.

9. The image forming apparatus as claimed in claim 1 , wherein the sub ASIC is an ASIC for single-color LSU control, and the main ASIC is an ASIC for four-color LSU control.

10. The image forming apparatus as claimed in claim 9, wherein the sub ASIC is to provide a video signal corresponding to a clear color or a transparent color to a single LSU, and the main ASIC is to provide video signals respectively corresponding to black, cyan, magenta, and yellow, to a corresponding LSU among the plurality of LSUs.

11. The image forming apparatus as claimed in claim 1 , wherein each of the plurality of LSUs includes a polygon mirror, and the image forming apparatus comprises a motor to rotate each of the polygon mirrors of the plurality of LSUs.

12. The image forming apparatus as claimed in claim 1 , wherein at least one of the LSUs includes: a light source device including a light source; a polygon mirror to deflect a beam output from the light source toward an organic photoconductor drum using a plurality of reflection surfaces; and a beam detection sensor to detect the beam deflected by the polygon mirror and to output a beam detection signal.

13. A non-transitory machine-readable storage medium encoded with instructions, that when executed, cause an image forming apparatus to: receive printing data; generate a plurality of video signals using the printing data; perform motor control for laser scanning units (LSUs) using one of a plurality of application specific integrated circuits (ASICs); and perform beam control for the LSUs using the plurality of video signals and the plurality of ASICs.

14. The non-transitory machine-readable storage medium as claimed in claim 13, wherein the non-transitory machine-readable storage medium is further encoded with instructions, that when executed, cause the image forming apparatus to perform the motor control so that a second horizontal synchronization signal corresponding to at least one LSU among the LSUs and a first horizontal synchronization signal corresponding to a plurality of LSUs other than the at least one LSU among the LSUs, have a preset time difference therebetween.

15. The non-transitory machine-readable storage medium as claimed in claim 13, wherein the plurality of ASICs include an ASIC for single-color LSU control and an ASIC for four-color LSU control, and the non-transitory machine-readable storage medium is further encoded with instructions, that when executed, cause the image forming apparatus to perform the motor control for the LSUs by using the ASIC for four-color LSU control.