JP4713388B2 - Image forming apparatus and image forming method - Google Patents

Description

  The present invention relates to an image forming apparatus such as an MFP, and more particularly to an image forming apparatus and an image forming method for separating a drum belt from a YMC drum in a monochrome mode.

  Recently, color image formation is becoming common in image forming apparatuses such as MFPs. For example, color images and monochrome images are formed in a quadruple tandem multifunction peripheral or the like. At this time, the drum belt is separated from the YMC photosensitive drum.

Patent Document 1 discloses a YMC drum separation operation as appropriate according to the remaining life information of the image carrier so as not to cause a decrease in productivity even in a print job for alternately printing a monochrome document and a color document. The case where it performs is shown, and the lifetime countermeasure is taken by this.
JP 2005-99436.

  However, in the prior art of Patent Document 1, a specific and accurate timing of the YMC drum separating operation of the drum belt is not shown. Therefore, for example, if the user selects the color mode and starts to separate the drum belt when the start key is pressed, the operation is not optimal in terms of timing. Therefore, for example, after a delay of several seconds, monochrome image formation is performed. There is a problem that will be done.

  In order to solve such a problem, an operation unit (40) for instructing whether to form a monochrome image or a color image of an original image, and insertion of the original document are detected by a first sensor (17) and automatically The second document (18) detects the original conveyed by the automatic original conveying unit (16), the original conveyed by the automatic original conveying unit, or the original directly placed on the original table, A reading unit (1) that reads an image of an original, an image forming unit (2) that forms an image on a recording medium based on the image of the original using a YMCK photosensitive drum and a drum belt, and the operation unit is monochrome When the first sensor or the second sensor detects the original, the drum belt is separated from the YMC drum and brought into contact with the K drum at this timing, and the recording is performed. When a monochrome image of the original is formed on a medium and the operation unit receives an instruction to form an image in color, and the first sensor or the second sensor detects the original, the timing is An image forming apparatus comprising: a control unit (30) for controlling the YMCK drum so that a color image of the original is formed on the recording medium by bringing a drum belt into contact with the YMCK photosensitive drum. It is.

  Since the operation of separating the drum belt from the YMC drum is performed at the optimal timing when the document is supplied, there is no delay in image formation as in the prior art, and rapid image formation can be performed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Image Forming Apparatus According to One Embodiment of the Present Invention>
(Mechanical Configuration of Image Forming Apparatus According to One Embodiment of the Present Invention)
First, an example of the configuration of a composite image forming apparatus according to an embodiment of the present invention will be described. 1 is a cross-sectional view showing an example of the configuration of an image forming apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram showing an example of the electrical configuration of the image forming apparatus, and FIG. FIG. 4 is a flowchart showing an example of the drum belt separating operation of the image forming apparatus according to the embodiment of the present invention.

  In these drawings, the digital color copying machine is composed of a scanner unit 1 as a reading function and a printer unit 2 as an image forming function.

  A scanner unit 1 that reads an image of a document has a document table cover 3 at the top thereof, and is opposed to the document table cover 3 in a closed state, and has a document table 4 made of transparent glass on which a document D is set. is doing. Below the document table 4, an exposure lamp 5 for illuminating the document D placed on the document table 4, a reflector 6 for condensing light from the exposure lamp 5 on the document D, and reflected light from the document D A first mirror 7 or the like that is bent in the left direction in FIG. The exposure lamp 5, the reflector 6, and the first mirror 7 are fixed to the first carriage 8. The first carriage 8 is connected to a pulse motor (not shown) via a toothed belt (not shown) and the like, and the driving force of the pulse motor is transmitted to move in parallel along the document table 4.

  An imaging lens 13 that forms an image of the reflected light from the second carriage 9 at a predetermined magnification is disposed in a plane including the optical axis of the light reflected through the second carriage 9. A CCD image sensor (photoelectric conversion element) 15 for converting the reflected light, which is focused by the imaging lens 13, into an electrical signal, that is, image data, is disposed in a plane substantially orthogonal to the optical axis of the light that has passed through 13. Has been.

  The printer unit 2 is based on a well-known subtractive color mixing method and performs color separation for each color component, that is, black (black, hereinafter referred to as k), magenta (a type of red, hereinafter referred to as m), First to fourth image forming units K6, M6, C6, and Y6 for forming four color images of cyan (bluish purple, hereinafter referred to as c) and yellow (yellow, hereinafter referred to as y), respectively. Have.

  Below each of the image forming units K6, M6, C6, and Y6, an intermediate transfer belt 21 that conveys an image of each color formed by each image forming unit in the direction of arrow a in the figure is disposed. The intermediate transfer belt 21 runs endlessly at a constant speed in the direction of arrow a, and the image forming units K6, M6, C6, and Y6 are arranged in series along the conveyance direction of the intermediate transfer belt 21.

  Each of the image forming units K6, M6, C6, and Y6 is a photosensitive drum K1, C1, M1, and an image carrier that is formed so that its outer peripheral surface is rotatable in the same direction at a position in contact with the intermediate transfer belt 21. Y1 is included. A drum motor (not shown) for rotating each photosensitive drum at a predetermined peripheral speed is connected to each photosensitive drum.

  The axes of the respective photoconductive drums K1, C1, M1, and Y1 are arranged so as to be orthogonal to the direction in which the image is conveyed by the intermediate transfer belt 21, and the axes of the photoconductive drums are arranged at equal intervals. In the following description, the axial direction of each photosensitive drum is defined as a main scanning direction (second direction), and the direction in which the photosensitive drum is rotated, that is, the rotation direction of the conveying belt 21 (the direction of arrow a in the figure). The sub-scanning direction (first direction) is assumed.

  Around each of the photosensitive drums K1, C1, M1, and Y1, there are charging devices K2, C2, M2, and Y2 as charging means extended in the main scanning direction, and developing means similarly extended in the main scanning direction. Development rollers K8, C8, M8, and Y8 as transfer rollers K5, C5, M5, and Y5 as transfer means similarly extended in the main scanning direction, respectively, along the rotation direction of the corresponding photosensitive drum. Arranged in order.

  Each primary transfer device is disposed at a position where the intermediate transfer belt 21 is held between the corresponding photosensitive drums, that is, inside the intermediate transfer belt 21. Further, exposure points by an exposure device to be described later are formed on the outer peripheral surface of the photosensitive drum between the charging device and the developing roller.

  Further, a secondary transfer roller is in contact with the intermediate transfer belt 21, and an image is transferred from the intermediate transfer member to the recording paper by passing a recording medium between the intermediate transfer belt 21 and the secondary transfer roller. .

  A misalignment sensor 201 for detecting the position of an image formed on the intermediate transfer belt 21 is disposed at one end of the intermediate transfer belt 21. The misalignment sensor 201 is configured by a transmissive or reflective optical sensor, and is connected to a control unit 202 including a printer CPU 110, a ROM 111, a RAM 112, and the like described in detail in FIG.

  Each of the exposure units K3, C3, M3, and Y3 that forms an electrostatic latent image that is color-separated on the outer peripheral surface of each photosensitive drum irradiates the laser beam for each color toward the exposure position of each photosensitive drum. To do.

(Electrical Configuration of Image Forming Apparatus According to One Embodiment of the Present Invention)
FIG. 3 is a block diagram schematically showing a signal flow for electrical connection and control of the digital color copying machine in FIG. As shown in FIG. 3, the digital color copying machine is composed of three CPUs: a main CPU 31 in the main control unit 30, a scanner CPU 100 in the scanner unit 1, and a printer CPU 110 in the printer unit 2. The main CPU 31 performs bidirectional communication with the printer CPU 110 via the shared RAM 35. The main CPU 31 issues an operation instruction, and the printer CPU 110 returns a status status. The printer CPU 110 and the scanner CPU 100 perform serial communication, the printer CPU 110 issues an operation instruction, and the scanner CPU 100 returns a status status.

  The control panel 40 is connected to the main CPU 31 and includes a panel CPU 41 that controls the whole, a liquid crystal display 42, and a print key 43. By the processing of the panel CPU 41 and the main CPU 31 to be described later, a tree-like display of the network and a plurality of devices is performed.

  The main control unit 30 includes a main CPU 31, a ROM 32, a RAM 33, an NVM 34, a shared RAM 35, an image processing device 36, a page memory control unit 37, a page memory 38, a printer controller 39, and a printer font ROM 121.

  The main CPU 31 controls the entire main control unit 30. The ROM 32 stores a control program. The RAM 33 temporarily stores data.

  An NVM (non-volatile RAM) 34 is a non-volatile memory backed up by a battery (not shown), and holds data on the NVM 34 when the power is turned off.

  The shared RAM 35 is used for bidirectional communication between the main CPU 31 and the printer CPU 110.

  The page memory control unit 37 stores or reads out image data in the page memory 38. The page memory 38 has an area where image data for a plurality of pages can be stored, and is formed so that data obtained by compressing image data from the scanner unit 1 can be stored for each page.

  The printer font ROM 121 stores font data corresponding to print data.

  The printer controller 39 stores print data from external devices 124-1 to 124-n on a network such as a personal computer in the printer font ROM 121 at a resolution corresponding to the data indicating the resolution given to the print data. The image data is developed using the existing font data.

  As an example, the interface 122 serving as a communication unit is an interface connected to the Internet via Ethernet (registered trademark) or the like. Similarly, the interface 123 serving as a communication unit is an interface for communicating with a plurality of devices 124-1 to 124-n on the network in accordance with a communication protocol such as Ethernet. Further, the communication protocol here does not necessarily need to be Ethernet, but may be IEEE (Institute of Electrical and Electronics Engineers) 1394 or USB (Universal Serial Bus). In addition, it is also preferable to have all of a plurality of interfaces for simultaneously performing these networks based on Ethernet, IEEE 1394, USB, or other communication protocol.

  The scanner unit 1 moves a scanner CPU 100 that controls the entire scanner unit 1, a ROM 101 that stores control programs and the like, a data storage RAM 102, a CCD driver 103, an exposure lamp 5 and mirrors 7, 11, and 12. The scan motor driver 104 controls the rotation of the motor.

  The printer unit 2 includes a printer CPU 110 that controls the entire printer unit 2, a ROM 111 that stores a control program, a RAM 112 for data storage, and a laser driver that turns on / off light emission by the exposure devices K 3, C 3, M 3, and Y 3. 113, a paper conveyance unit 115 that controls conveyance of the paper P by the conveyance mechanism, a charging control unit 114 that controls bias to the chargers K2, C2, M2, and Y2, and a bias to the developing rollers K8, C8, M8, and Y8 A development control unit (separation / contact process) 116 for controlling the transfer, a transfer control unit 118 for controlling the bias to the transfer rollers K5, C5, M5, and Y5, a fixing control unit 117 for controlling the fixing device 80, and an option The unit 118 is configured.

  The image processing device 36, the page memory 38, the printer controller 39, and the laser driver 113 are connected by an image data bus 120.

  The composite image forming apparatus having the above-described configuration not only forms an image of a document image captured by the scanner unit 1 on a sheet as a recording medium using the printer unit 2 according to various specifications provided. Fax transmission / reception and e-mail transmission / reception can be performed via the interface units 122 and 123 which are communication units. Furthermore, as will be described later, the tree structure on the network is displayed, image information is acquired from the devices on the network, printed, and the image information captured by the scanner is transferred to the specified devices on the network and stored. can do.

<Drum Belt Separation / Abutment Operation of Image Forming Apparatus According to One Embodiment of the Present Invention>
Next, the separation / contact operation of the photosensitive drum of the above-described image forming apparatus will be described in detail with reference to the flowchart of FIG.

  The photosensitive drum separation / contact operation during image formation is performed by the above-described development control unit (separation / contact processing unit) of the printer unit 2.

・ Summary The separation / contact operation of the photosensitive drum during image formation is not necessarily required when the drum belt separation operation is performed during the printing operation after the start key is pressed after pressing the start key of the 4-drum tandem MFP. Does not shorten, but leaves room for improvement. Therefore, in this embodiment, in order to shorten the first copy time of the quadruple tandem type multifunction peripheral, when the user selects the color mode of the operation screen and opens the glass surface cover before pressing the start key, or When the document is inserted into the automatic conveyance device, a drum belt separating operation is performed. Therefore, the first copy time is shortened by performing the drum belt separation operation before starting the print job.

  That is, when the operation unit receives an instruction to form a monochrome image and the first sensor 17 or the second sensor 18 detects a document, at this timing, the drum belt is separated from the YMC drum and brought into contact with the K drum. When a monochrome image of a document is formed on a recording medium and the operation unit receives an instruction to form a color image, and the first sensor 17 or the second sensor 18 detects the document, the drum is detected at this timing. The belt is brought into contact with the YMCK photosensitive drum, and the YMCK drum is controlled to form a color image of the original on the recording medium.

Operation Flowchart Next, details of the separation / contact operation of the photosensitive drum during image formation will be described using the flowchart of FIG.

  First, in order to shorten the first copy time of the 4-drum tandem type MFP, the user can change the color mode (full color, black, auto color) shown on the liquid crystal display unit 42 of the control panel 40 before pressing the start key. Whether or not is selected is determined (step S11). Here, the following two conditions are suitable as preset conditions.

Setting 1: Setting whether to default black or default color to the “auto color” icon Setting 2: When performing auto color printing, perform a drum belt separation operation for monochrome documents. Here, a selection icon of “full color”, “black” and “auto color” is provided on the operation screen of the MFP. Press the “Full Color” icon to enter Full Color mode. When the “black” icon is pressed, the black mode is set. When the “auto color” icon is pressed, the mode set in setting 1 is set.

  Next, either “when the document is placed on the glass surface” or “when the document is inserted into the automatic document feeder” is detected (step S12). “When the document is placed on the glass surface” is detected by the sensor 18 of FIG. “When the document is inserted into the automatic document feeder” is detected by the sensor 17. However, a method in which the automatic document transport unit 16 is lifted by the sensor 19 to detect that the process of placing the document on the glass surface is in progress is also suitable.

  Next, the previous color icons are distinguished, and a full color icon, an auto color icon, or a black icon is distinguished (steps S13 to S15).

  If it is an auto color icon, it is determined whether or not black of setting 1 is set, and if so, it is asked whether separation is selected for a monochrome document at ACS (step S17).

(1) When printing by selecting the “full color” icon, the controller notifies the controller of the full color mode from the UI layer, and issues a drum belt separation instruction from the controller to the machine (no separation: printing without separating the YMCK drum belt) thing). (Step S19)
(2) When printing by selecting the “black” icon, the controller notifies the controller of the black mode from the UI layer, and the controller issues an instruction to separate the drum belt to the machine (with separation: the YMC drum is separated and the K drum is separated). (Print without printing) (step S18). As a result, as shown in FIG. 2, the drum belt is separated from the YMC drum.

  (3) When the “auto color” icon is selected and printed, if the color mode is set for the “auto color” icon in setting 1, an instruction indicating no separation is issued from the controller to the machine (step S19). When the black mode is set for the “auto color” icon, if there is a separation in setting 2, a separation instruction is issued from the controller (step S 18). As a result, as shown in FIG. 2, the drum belt is separated from the YMC drum. If the setting 2 is a setting for no separation, an instruction for no separation is issued from the controller (step S19).

  As described above, according to the embodiment of the present invention, in order to perform the drum belt separating operation when the user presses the icon and sets the document, the waiting time is 2 to 3 seconds compared with the case where the separating operation is started by the start key. Since the time disappears, the first copy time is shortened.

  With the various embodiments described above, those skilled in the art can realize the present invention. However, it is easy for those skilled in the art to come up with various modifications of these embodiments, and have the inventive ability. It is possible to apply to various embodiments at least. Therefore, the present invention covers a wide range consistent with the disclosed principle and novel features, and is not limited to the above-described embodiments.

1 is a cross-sectional view illustrating an example of a configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 3 is a cross-sectional view showing an example of a configuration when drum belt separation is performed in the image forming apparatus according to the embodiment of the present disclosure. 1 is a block diagram illustrating an example of an electrical configuration of an image forming apparatus according to an embodiment of the present invention. 6 is a flowchart illustrating an example of a drum belt separation operation of the image forming apparatus according to the embodiment of the present disclosure.

Explanation of symbols

  30 ... main control unit, 31 ... main CPU, 2 ... printer unit, 21 ... drum belt.

Claims (8)

An operation unit for instructing whether to form a monochrome image or a color image of an original image;
An automatic document feeder that detects insertion of the document with a first sensor and automatically conveys the document;
A reading unit that detects the document conveyed by the automatic document conveyance unit or the document directly placed on the document table with a second sensor and reads an image of the document;
An image forming unit that forms an image on a recording medium based on an image of the original using a YMCK photosensitive drum and a drum belt;
When the operation unit receives an instruction to form an image in monochrome, and the first sensor or the second sensor detects the original, the drum belt is separated from the YMC drum at this timing and is in contact with the K drum. The monochrome image of the document is formed on the recording medium, the operation unit receives an instruction to form a color image, and when the first sensor or the second sensor detects the document, A control unit that controls the YMCK drum so that the color image of the original is formed on the recording medium by bringing the drum belt into contact with the YMCK photosensitive drum at this timing. Image forming apparatus.   2. The image forming apparatus according to claim 1, wherein the operation unit performs automatic setting with one of monochrome printing and color printing as a default.   2. The image forming apparatus according to claim 1, wherein, in the operation unit, when the document image read by the reading unit is monochrome, the drum belt is separated from the YMC drum.   The controller controls the drum belt from the YMC drum at a timing to detect that the automatic document feeder is opened by an open / close sensor of the automatic document feeder instead of the first sensor or the second sensor. The image forming apparatus according to claim 1, wherein the image forming apparatus is separated. Receive instructions to form a monochrome image,
When document placement is detected by a first sensor that detects insertion of a document in the automatic document feeder or a second sensor provided on the document table,
At this timing, the drum belt is separated from the YMC drum,
Forming a monochrome image of the original on the recording medium with only the drum belt and the K drum;
Receive instructions to form an image in color,
When the first sensor or the second sensor detects the document,
At this timing, the drum belt and the YMCK photosensitive drum are brought into contact with each other,
An image forming method comprising: forming a color image of the original on the recording medium by the drum belt and the YMCK drum.   6. The image forming method according to claim 5, wherein automatic setting is performed with one of monochrome printing and color printing as a default.   6. The image forming method according to claim 5, wherein when the detected document image is monochrome, the drum belt is separated from the YMC drum.   Instead of the first sensor or the second sensor, the drum belt is separated from the YMC drum at a timing when the opening / closing sensor of the automatic document conveying unit detects that the automatic document conveying unit is opened. The image forming method according to claim 5.

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