JP2005140944A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of performing printing operation only by an attached ID unit and preventing an LED head for an unattached ID unit from being soiled. <P>SOLUTION: The image forming apparatus which forms an image by freely attachably/detachably mounting a corresponding image forming unit to each of a plurality of image forming unit attaching parts is equipped with an exposure part provided corresponding to each of the image forming unit attaching parts, and a covering member with which the exposure part is covered so that the light emitting port of the exposure part may be protected from surrounding suspended matter. Each of the image forming unit attaching parts has an image forming unit detection means for detecting the existence of the corresponding image forming unit. The image forming unit detection means detects the covering member when the covering member is attached. The covering member is positioned to cover over the image forming unit detection means when image forming action is performed. Each of the image forming unit attaching parts has a covering member detection means for detecting the existence of the corresponding covering member. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electrophotographic image forming apparatus.

  There are two types of electrophotographic printers: a single-color printer that can print only a single color and a color printer that can perform full-color printing. In recent years, an increasing number of users have purchased as monochrome printers and want to purchase yellow, magenta, and cyan ID units and use them as color printers to add color printing functions later. In addition, there are users who want to purchase and print only an ID unit of a specific color for the purpose of frequently using only a specific color, such as monochrome. The conventional color printer has the following problems when trying to use it in this way.

JP-A-10-187002

  In a conventional color printer equipped with four color ID units, the ID unit sensor detects whether each ID unit is installed and sends a detection signal to a control unit (not shown). If there is an unattached ID unit, the control unit outputs a command for prohibiting the printing operation and displays on the LCD display unit that the normal operation cannot be performed. That is, in the conventional color printer, if there is an unmounted ID unit, the printing operation is prohibited.

  Even if the image forming apparatus is designed so that at least monochrome printing can be performed when only the black ID unit is mounted, the other ID units may be affected by the flow of air generated when the paper is conveyed. Black toner floats in the space where it is installed. Further, when the LED head is employed as the exposure apparatus, the corresponding ID unit is not mounted, so that the optical system including the irradiation unit remains exposed with respect to the floating toner. If the floating toner adheres to the SLA (Selfoc Lens Array), there is a problem that the print quality is deteriorated when the color ID unit is mounted and color printing is performed. In addition, the accumulation of paper dust generated from the paper or the accumulation of dust in the portion where the color ID unit is mounted while the image forming apparatus is stored for a long period of time is also a problem.

  An object of the present invention is to provide an image forming apparatus that can perform a printing operation only with a mounted ID unit and that does not stain an LED head for an unmounted ID unit.

  The present invention has been made to solve the above-described problems of the conventional apparatus. An image forming apparatus according to the present invention is an image forming apparatus that forms an image by detachably attaching a corresponding image forming unit to each of a plurality of image forming unit mounting portions. The exposure part provided correspondingly, and the coating | coated member which covers the said exposure part and protects the exit of the said exposure part light from a surrounding floating substance, It is characterized by the above-mentioned.

  Each of the image forming unit mounting portions includes an image forming unit detection unit that detects the presence or absence of the corresponding image forming unit.

  The image forming unit detection means detects the covering member when the covering member is mounted.

  The covering member is positioned so as to cover the image forming unit detection means during an image forming operation.

  Each of the image forming unit mounting portions includes a covering member detection unit that detects the presence or absence of the corresponding covering member.

In the image forming apparatus, each of the image forming unit mounting portions includes an image forming unit detecting unit that detects presence / absence of the corresponding image forming unit,
Covering member detecting means for detecting the presence or absence of the corresponding covering member, wherein the covering member is detected by both the image forming unit detecting means and the covering member detecting means.

The image forming apparatus includes: an image forming unit detecting unit that detects presence / absence of the corresponding image forming unit in each of the plurality of image forming unit mounting portions; and a covering member detecting unit that detects presence / absence of the corresponding covering member. And
Based on the detection output of the image forming unit detection means and the detection output of the covering member detection means, it is determined whether or not the image forming unit and the covering member are attached to the corresponding image forming unit attachment portion. It further has a determination unit.

The image forming apparatus includes an operation mode setting unit that sets an image forming operation mode based on a determination result of the determination unit.
The image forming function unit is an exposure unit that forms an electrostatic latent image on a photoconductor provided in the image forming unit, and the covering member covers a light emission port of the exposure unit.

  The image forming apparatus further includes a display unit, and the display unit displays a determination result of the wearing state determination unit when the operation mode is set.

  The image forming apparatus further includes an operation unit, and the mounting state determination unit sets an operation mode corresponding to a determination result of the mounting state determination unit based on a command input via the operation unit. Decide whether to do it.

  When the mounting state determination unit determines that no image forming unit is mounted on the image forming unit mounting unit, the mounting state determination unit prohibits the image forming operation.

  In the image forming apparatus, when the mounting state determination unit determines that either the image forming unit or the covering member is not mounted on at least one image forming unit mounting unit, the mounting state determination unit Prohibits the image forming operation.

  The image forming apparatus includes a comparison unit that compares a determination result of the mounting state determination unit with a mounting unit of an image forming unit corresponding to a preset operation mode.

  The image forming apparatus includes a display unit that displays a comparison result by the comparison unit.

  The image forming apparatus further includes an operation unit, and if the comparison result by the comparison unit does not match, the mounting state determination unit inputs a command to be input via the operation unit as to whether or not to set an operation mode. Determine based on.

The image forming apparatus further includes a speed control unit that controls an operation speed of image formation,
The speed control unit determines an image forming speed according to the number of mounted image forming units determined by the mounting state determining unit.

  Printing operation is possible only with the mounted ID unit, and the LED head for the unmounted ID unit is not soiled.

Embodiment 1
FIG. 1 is a schematic view of an LED color printer according to the present invention in which an ID unit is detachable. A sheet receive 2 is provided on the outlet side of the sheet feeding cassette 1 and is pushed upward by a pushing spring (not shown). The leading end side of the paper stored in the paper feed cassette 1 is placed on the sheet receive 2. The sheet receive 2 urges the paper against the paper feed roller 51 and the paper feed sub-roller 52 from below the paper. When the paper feed roller 51 and the paper feed sub-roller 52 are driven by a transport motor (not shown), the paper stored in the paper feed cassette 1 is fed to the transport path page by page. The sheet is sandwiched between a registration roller 53 and a pressure roller 54 that are rotated by a conveyance motor, and proceeds in the conveyance path. The sheet advances while being guided in the conveyance path, and is nipped between the pressure roller 55 and the pressure roller 56 that is press-engaged with the pressure roller 55, and is conveyed toward the conveyance belt unit.

  The conveyor belt unit includes a belt driving roller 57 driven by a belt motor (not shown), a conveyor belt 3, an idle roller 58, and transfer rollers 59-62. The conveyor belt 3 is tensioned by the belt driving roller 57 and the idle roller 58. The transfer roller applies a transfer voltage to the photosensitive drums 31-34 of the ID unit 4-7 via the belt. When the sheet is placed on the belt and passes through the ID unit 4-7, toner images of K (black), Y (yellow), M (magenta), and C (cyan) are transferred from the photosensitive drum 31-34. And transferred onto the paper.

  The fixing device 40 includes a fixing roller 63 and a pressure roller 64. The fixing roller 40 includes a halogen lamp (not shown) and is heated by the halogen lamp. The fixing roller 63 is pressed and engaged with the pressure roller 64 and is rotated by a fixing motor (not shown). The sheet on which the toner image of each color is transferred is drawn between the fixing roller 63 and the pressure roller 64 and heated to fix the toner image. The paper is discharged onto the face-up portion 8a of the face-up stacker 8 by the discharge rollers 65 and 66 driven by the fixing motor.

  When the face-up stacker 8 is closed in the direction of the arrow A, the face-up stacker 8 acts as a paper guide, and a discharge roller 69 driven by a fixing motor, and a pressure roller 68 that press-engages with the discharge roller 69. The paper is conveyed while being sandwiched between the top cover 9 and discharged to the face-down portion 9 a of the top cover 9. During the period during which the sheet is conveyed, the LCD display unit 30 displays that the printing operation is being performed.

  An inner plate 10 is attached to the top cover 9, and head holders 21-24 for each color are held. Each head holder 21-24 is provided with each LED head portion 11-14, and an LED is irradiated from the LED head portion to form an electrostatic latent image on the photosensitive drum.

  FIG. 2 shows a state in which the top cover of the LED color printer shown in FIG. 1 is opened. As shown in FIG. 2, when the top cover 9 is opened in the direction of arrow B, the four head holders 20 fixed by the inner plate 10 and the LED heads attached to the head holder 20 are connected to the top cover 9 and the inner plate. Since it is revolved around the 10 rotation shafts and retracted, a space for putting a hand is created, and the ID unit 4-7 can be easily taken out.

  FIG. 3 is a side view showing a state in which only the ID unit K4 is mounted. 4 is an external view showing the head cover as viewed from the direction of arrow C in FIG. FIG. 5 is a cross-sectional view taken along line AA in FIG.

  The color printing apparatus of the present invention can perform printing operation with only a monochrome ID unit mounted, but in FIG. 3, the space for the color ID unit 5-7 has the ID unit 5- 7 shows a state where it is not attached. As shown in FIG. 4, each LED head 11-14 is provided in a corresponding color ID unit and functions as an exposure apparatus. As shown in FIG. 5, a head cover 601 is attached to the LED head via a latch portion 601a. Further, the sensor cover 601b (FIG. 6) that extends long is opposed to the light emitting surface of the ID unit sensor 502 so as to cover the light emitting surface of the corresponding ID unit sensor attached to the apparatus main body. The ID unit sensor 501 detects that the ID unit is mounted by emitting light toward the ID unit and receiving reflected light.

  FIG. 6 shows the relationship between the LED head Y12 attached to the head cover 601 and the ID unit K4. Further, as shown in FIG. 6, the head cover 601 covers the light emitting part of the LED head part Y12, and protects the optical part from floating toner 562, paper dust, and dust that are likely to occur during the printing operation. Therefore, paper dust and dust only adhere to the outer surface of the cover 601. As shown in FIG. 5, the head cover 601 can be easily removed by operating the latch portion 601a. For example, when the Y ID unit 5 is mounted, the head cover 601 attached at the Y position is removed. If the ID unit Y5 is removed and the ID unit Y5 is attached, printing with two colors K and Y becomes possible. The same applies when the M or C ID units 6 and 7 are mounted. Further, since the sensor cover 601b covers the surface of the reflective ID unit sensor 502, the optical part of the sensor can be protected from paper dust and dust.

  FIG. 7 is a cross-sectional view of the LED head portion. The LED head includes an LED array chip 301, an SLA (convergent rod lens array) 302, and an SLA holder 303. The LED array chip 301 is mounted on a substrate 304, and the SLA 302 is held by an SLA holder 303. The SLA holder 303 holds the substrate 304, the base 305, and the SLA 302 and accurately positions the surface of the photosensitive drum 306. Light with high coherence (hereinafter referred to as coherent light) emitted from the LED array chip 301 is converged on the photosensitive drum 306 by the SLA 302 to form an electrostatic latent image on the photosensitive drum.

  FIG. 8 shows a control block of the first embodiment. Hereinafter, a description will be given with reference to FIG. In FIG. 8, a print control unit 100 includes a microprocessor, a ROM, a RAM, an input / output port, a timer, and the like. The print control unit 100 receives print data and control commands from a host device, and performs printing by controlling the entire operation of the printer unit. Perform the action. The I / F control unit 110 transmits printer information to the host device, analyzes a command received from the host device, and processes data received from the host device.

  The reception memory 120 stores the data received from the host device for each color according to the control of the I / F control unit 110. The operation unit 101 includes an LED for displaying the status of the printer and a switch for an operator to input a command to the printer. The sensor group 102 includes a plurality of sensors that detect the transport position of the print medium, a sensor that detects temperature and humidity in the apparatus, a sensor for density measurement, and the like, and the output of each sensor is input to the print control unit 100. .

  The image editing memory 130 receives the print data temporarily stored in the reception memory 120 and stores the edited image data. The print control unit 100 transmits the image data stored in the image editing memory 130 to the print heads 151-154. The charging voltage control unit 140 applies a voltage to each charger in accordance with a command from the print control unit 100 to perform control for charging the surface of the corresponding photosensitive drum. The charging control unit 140 includes a K charging voltage control unit, a Y charging voltage control unit, an M charging voltage control unit, and a C charging voltage control unit. The K charging unit 141, the Y charging unit 142, and the M charging unit, respectively. 143 and the voltage applied to the C charger 144 are controlled.

  The head controller 150 includes a K head controller, a Y head controller, an M head controller, and a C head controller. The head control unit 150 transmits image data to the corresponding K head 151, Y head 152, M head 153, and C head 154 at a predetermined timing. Each head irradiates the corresponding photosensitive drum surface with light according to the image data stored in the image data editing memory 130 to form an electrostatic latent image.

  The development voltage control unit 160 includes a K development voltage control unit, a Y development voltage control unit, an M development voltage control unit, and a C development voltage control unit. Each development voltage control unit includes a K development unit 161 and a Y development unit. The voltage applied to the developing device 162, the M developing device 163, and the C developing device 164 is controlled. The developing voltage control unit 160 controls the voltage applied to each developing device and attaches toner to the electrostatic latent image formed on the surface of the corresponding photosensitive drum, thereby forming a toner image.

  The transfer voltage control unit 170 includes a K transfer voltage control unit, a Y transfer voltage control unit, an M transfer voltage control unit, and a C transfer voltage control unit. Each transfer voltage control unit includes a K transfer unit 171 and a Y transfer unit. The voltage applied to the transfer device 172, the M transfer device 173, and the C transfer device 174 is controlled. In accordance with a command from the print control unit 100, the transfer control unit 170 sequentially transfers the toner images formed by the developing units to the print medium when the paper passes through the transfer units.

  The motor control unit 180 drives a K motor control unit, a Y motor control unit, an M motor control unit, and a C motor control unit, respectively, and drives a photosensitive drum, a charger, and a developing unit. 182, the M motor 183 and the C motor 184 are driven.

  The fixing control unit 190 controls the voltage applied to the heater built in the fixing device 191 in accordance with an instruction from the printing control unit, and fixes the toner image transferred to the printing medium. The thermistor 192 measures the temperature of the fixing device 19. The fixing controller 190 receives the detected temperature value from the thermistor 192 and controls the heater on / off. When the fixing device rises to a predetermined temperature, the fixing controller 190 controls the fixing device motor 193 to rotate the fixing device and start the fixing operation.

  The conveyance motor control unit 200 controls the conveyance motor 205 to drive the conveyance belt 3 for conveying the print medium.

  Next, the general operation of the printer configured as described above will be described. The print control unit 100 receives various control commands, print data, and the like from the host device via the I / F control unit 110. When a printing command is received from the host device, first, a command is issued to the fixing control unit 190, and the thermistor 192 detects whether or not the fixing device 191 is within a predetermined temperature range in which it can operate. If the detected temperature is below the lower limit value of the temperature range, the heater is turned on and the fixing device 191 is heated until the temperature falls within the temperature range. When the fixing device 191 rises to a predetermined temperature, the fixing control unit 190 outputs an instruction to the fixing device motor 193 to drive the fixing motor 193 to rotate the fixing device 191.

  Next, the print control unit 100 drives each photosensitive drum, charger, and developing device motor via the motor control unit 180. At the same time, a command is issued to the charging controller 140, the development voltage controller 160, and the transfer voltage controller 170, and a voltage is applied to the charger, developer, and transfer unit corresponding to each color. The print control unit 100 starts the conveyance of the print medium after detecting the print medium stored in a paper cassette (not shown) via the paper material sensor and the paper size sensor. Here, the print medium transport motor 205 can be driven in both directions. By first driving in the reverse direction, the print medium is taken out of the paper cassette and detected by the paper inlet sensor. It is sent out by the set feed amount. Subsequently, the print medium is driven into the printing mechanism of the printer by driving the print medium transport motor in the forward direction.

  The print controller 100 sends a timing signal when the print medium reaches a printable position, reads the image data from the image data editing memory 130, and sends it to the head controller 150. Then, when the head controller 150 receives one line of image data, the head controller 150 sends a latch signal to the LED head as an exposure unit, and holds the image data in the LED head. Further, the head controller 150 sends a print drive signal STB to the LED head before receiving the next timing signal. As a result, the LED head starts forming an electrostatic latent image for each line on the photosensitive drum according to the held image data.

  That is, the LED head irradiates a photosensitive drum charged with a negative potential, and forms a large number of dots with increased potential on the surface of the photosensitive drum. These dots as a whole form an electrostatic latent image. Toner charged to a negative potential is attracted to each dot by Coulomb force to form a toner image. Thereafter, the toner image is sent to a transfer portion formed between the photosensitive drum and the transfer device.

  On the other hand, the print control unit 100 instructs the transfer voltage control unit 170 to apply a positive transfer high voltage to the transfer unit. As a result, the transfer device transfers the toner image to the print medium passing through the transfer portion. Then, the print medium on which the transferred toner image is placed is sent to the fixing device, and the toner image is fixed to the print medium by the heat of the fixing device 191. The print medium having the fixed toner further proceeds, and is discharged from the printer printing mechanism to the outside of the printer through the paper discharge port sensor. When the printing is completed and the print medium paper discharge port sensor is passed, the application of voltage to the charging device, the developing device, and the transfer device is finished, and at the same time, the operation of each motor is stopped. Thereafter, the printing is repeated for each page of the medium.

  According to the first embodiment, even when any ID unit is not mounted, if a head cover having a portion facing the ID unit sensor is attached to the LED head so as to cover the ID unit sensor, Even if no special condition is added, it is possible to recognize that the ID unit is mounted in a pseudo manner, and monochrome or multicolor printing such as monochrome can be performed. In addition, the optical part such as the LED head part and the optical sensor can be protected.

  For example, a laser-type color printer using coherent light has an optical unit that forms an electrostatic latent image by irradiating light, and printing is possible without mounting all ID units. The first embodiment can also be applied to an image forming apparatus having such a configuration.

Embodiment 2
FIG. 9 is a side view showing the apparatus according to the second embodiment. In addition to ID unit sensors 501 to 504 for detecting each ID unit, a reflection type cover sensor 511 to 514 for detecting each head cover 611 is attached to the apparatus main body. The inner plate 10 in front of the head cover sensor is provided with a hole 10a so that light emitted from the head cover sensor can reach the head cover without being blocked. The head cover 611 is attached to each color LED head 12-14 and faces the light emission surface of the LED head through the hole 10a. The head cover 611 has a latch portion similar to the head cover 601 of the first embodiment, and is easy to remove.

  FIG. 10 is an external view showing the head cover. As can be seen from FIG. 10, the head cover 611 has a sensor cover 601b that extends long, and the sensor cover 601b is shaped to face the ID unit sensors 502-504 attached to the apparatus main body. In addition, a sensor cover portion 601d is newly provided, and is configured to face the cover sensors 512-514 of the Y, M, and C heads.

  FIG. 11 is a block diagram illustrating a control unit according to the second embodiment. This control unit will be described with reference to FIG. The sensor group 811-814 corresponding to each color includes ID unit sensors 501, 502, 503, and 504 that detect the ID unit of each color, and head cover sensors 511, 512, 513, and 514. The operation mode setting unit 804 has a setting mode for single color printing, a multi-color printing mode, and a setting mode for full color printing as the printing operation mode in addition to the operation mode for prohibiting the printing operation.

  The control unit 801 receives detection signals from the sensor groups 811, 812, 813, and 814, and stores them in the detection result storage unit 801b. The comparison unit 801a compares the mode setting set by the operation mode setting unit with the detection signal stored in the detection result storage unit 801b. If at least one sensor group has detected neither the ID unit nor the sensor cover of the head, the control unit 801 outputs a command for prohibiting the printing operation to the operation mode setting unit 804 and also displays it on the display unit 802. Command the display to prohibit printing operations.

  Next, when any sensor group detects the ID unit and does not detect the sensor cover of the head, the control unit 801 recognizes that all the ID units are correctly mounted and performs a color printing operation. The command is output to the operation mode setting unit 804 and the display unit 802 displays that the color printing operation is being performed.

  When at least one sensor group detects an ID unit and detects a cover sensor of the head, the control unit 801 displays that a single color ID unit or a plurality of non-total ID units are correctly mounted. The message is displayed on the section 802 and the user is inquired whether or not to perform the printing operation.

  Viewing the display on the display unit 802, the user determines whether or not to perform a printing operation. When a command for prohibiting the printing operation is displayed on the display unit, the user inputs a command for prohibiting the printing operation via the operation unit 803.

  When receiving a command to perform a printing operation via the operation unit 803, the control unit outputs a command to perform a printing operation to the operation mode setting unit 804.

  The control unit 801 determines whether to perform printing in the single color setting mode, the multiple color setting mode, or the full color setting mode based on the detection result of the sensor group, and performs control according to the determination result in accordance with the operation mode setting unit. Command to 804. .

  The control unit 801 can determine which ID unit is attached by the sensor group 811-814. If an ID unit corresponding to the operation mode initially set by the operation mode setting unit 804 or the operation mode set by the user is not mounted, the display unit 802 displays that the mounting state is different, and the printing operation is performed. Ask the user if he should do it. The user inputs an operation mode via the operation unit 803. That is, the user resets the operation mode according to the detected ID unit, or inputs an operation prohibition when not resetting.

  FIG. 12 is a flowchart for explaining setting of the operation mode of the printer according to the present invention. In step S1, a subroutine for detecting which ID unit is mounted is executed. This subroutine will be described later with reference to FIG. In step S2, it is determined whether the operation mode input by the user via the operation unit matches the print mode set in step S1. If the determination in step S2 is NO, a warning is displayed on the display device in step S3. In step S4, it is determined whether or not the operation mode has been changed by the user. If the user selects not to change, the process proceeds to step S6, and the operation of the printer is prohibited. If the user selects to change, the process proceeds to step S5, and the user resets the operation mode. If YES in step S2, the initial setting program ends.

  When the user inputs an operation mode, the printer of the present invention checks whether each ID unit is mounted and determines a print mode corresponding to each mounted ID unit. If all ID units are installed, the full color mode is set. 13 and 14 show details of the subroutine of step S1 shown in FIG. This will be described in detail below with reference to FIGS.

  In step S101 of FIG. 13, it is determined whether or not the K unit sensor 501 is ON. If “NO” in the step S101, the process proceeds to a step S6 to prohibit the operation of the printer. If “YES” in the step S101, the process proceeds to a step S102 to determine whether or not the K head cover sensor 511 is ON. If YES at step S102, the process proceeds to step S125 of FIG. If NO in step S102, the K ID unit 501 is correctly attached.

  In step S103, it is determined whether the Y unit sensor 502 is ON. If “NO” in the step S103, the process proceeds to a step S6 to prohibit the operation of the printer. If “YES” in the step S103, the process proceeds to a step S104 to determine whether or not the Y head cover sensor 512 is ON. If NO in step S104, the Y ID unit is correctly attached, and the process proceeds to step S105.

  In step S105, it is determined whether the M unit sensor 503 is ON. If “NO” in the step S105, the process proceeds to a step S6 to prohibit the operation of the printer. If “YES” in the step S105, the process proceeds to a step S106 to determine whether or not the M head cover sensor 513 is ON. If NO in step S106, the M ID unit is correctly attached, and the process proceeds to step S107. If YES in step S106, the process proceeds to step S11 1.

  In step S107, it is determined whether or not the C unit sensor 504 is ON. If “NO” in the step S10 7, the process proceeds to a step S6 to prohibit the operation of the printer. If “YES” in the step S107, the process proceeds to a step S108, and it is determined whether or not the C head cover sensor 514 is ON. If NO in step S108, the C ID unit is correctly attached. That is, since all ID units are not attached, the full color mode is set in step S109.

  If YES in step S108, the flow advances to step S110 to set the KYM mode in which the K, Y, and M ID units operate.

  If YES in step S106, the flow advances to step S111 to determine whether the C ID unit sensor 504 is ON. If “NO” in the step S111, the process proceeds to a step S6 to prohibit the operation of the printer. If “YES” in the step S111, the process proceeds to a step S112 to determine whether or not the C head cover sensor 514 is ON. If NO in step S112, each ID unit of KYC is correctly attached, so the process proceeds to step S113, and the KYC mode in which the K, Y, and C ID units operate is set. If “YES” in the step S112, the process proceeds to a step S114 to set the KY mode.

  If “YES” in the step S104, the process proceeds to a step S115 to determine whether or not the M unit sensor 503 is ON. If NO in step S115, the process proceeds to S6 to prohibit the operation of the printer. If “YES” in the step S115, the process proceeds to a step S116 to determine whether or not the cover sensor 513 of the M head is ON. If NO in step S116, it means that the M ID unit is correctly attached, and the process proceeds to step S117 to determine whether the C unit sensor 504 is ON. If NO in step S117, the process proceeds to step S6, and the operation of the printer is prohibited. If “YES” in the step S117, the process proceeds to a step S118, and it is determined whether or not the C head cover sensor 514 is ON. If “NO” in the step S118, the K, M, and C ID units are correctly mounted, so the process proceeds to a step S119 to set the KMC mode in which the K, M, and C ID units operate.

  If YES in step S118, only the K and M ID units are correctly attached. Accordingly, the process proceeds to step S120, and the KM mode in which the K and M ID units operate is set.

  If “YES” in the step S116, the process proceeds to a step S121 to determine whether or not the C unit sensor 504 is ON. If “NO” in the step S121, the process proceeds to a step S6 to prohibit the operation of the printer. If “YES” in the step S121, the process proceeds to a step S122 to determine whether or not the C head cover sensor 514 is ON. If “YES” in the step S122, the process proceeds to a step S124 to set the K mode in which only the K ID unit is operated. If NO in step S122, only the K and C ID units are correctly attached, so the process proceeds to step S123 to set the KC mode in which the K and C ID units operate.

  If YES at step S102, control proceeds to step S125 of FIG. In step S125 of FIG. 14, it is determined whether or not the Y unit sensor 502 is ON. If “NO” in the step S125, the process proceeds to a step S6 in FIG. 2 to prohibit the operation of the printer. If “YES” in the step S125, the process proceeds to a step S126 to determine whether or not the Y head cover sensor 512 is ON. If “NO”, the Y ID unit is correctly attached.

  If “NO” in the step S126, the process proceeds to a step S127 to determine whether or not the M unit sensor 503 is ON. If “NO” in the step S127, the process proceeds to a step S6 to prohibit the operation of the printer. If “YES” in the step S127, the process proceeds to a step S128 to determine whether the cover sensor 513 of the M head is ON. If “NO” in the step S128, the M ID unit is correctly attached, and the process proceeds to the step S129.

  In step S129, it is determined whether or not the C unit sensor 504 is ON. If NO in step S129, the process proceeds to step S6 in FIG. 2, and the operation of the printer is prohibited. If “YES” in the step S129, the process proceeds to a step S130, and it is determined whether or not the C head cover sensor 514 is ON. If “NO” in the step S130, the C ID unit is correctly mounted, so the process proceeds to a step S131 to set the YMC mode in which the Y, M, and C ID units operate.

  If YES in step S130, the flow advances to step S132 to set the YM mode in which the Y and M ID units operate.

  If YES in step S128, the flow advances to step S133 to determine whether the C unit sensor 504 is ON. If NO in step S133, the process proceeds to S6 to prohibit the operation. If “YES” in the step S133, the process proceeds to a step S134 to determine whether or not the C head cover sensor is ON. If NO in step S134, only the Y and C ID units are correctly attached, so in step S135, the YC mode in which the Y and C ID units operate is set. If “YES” in the step S134, the process proceeds to a step S136 to set the Y mode in which the Y ID unit operates.

  If YES in step S126, it is determined in step S137 whether the M unit sensor 503 is ON. If NO in step S137, the process proceeds to S6 to prohibit the operation. If “YES” in the step S137, the process proceeds to a step S138 to determine whether or not the cover sensor 513 of the M head is ON. If “NO” in the step S138, the process proceeds to a step S139 to determine whether or not the head cover sensor 514 of the C head is ON. If NO in step S139, the process proceeds to S6 to prohibit the operation. If “YES” in the step S139, the process proceeds to a step S140, and it is determined whether or not the C head cover sensor 514 is ON. If NO in step S140, the M and C ID units are correctly attached. In step S141, the MC mode in which only the M and C ID units operate is set. If “YES” in the step S140, the M mode in which only the M ID unit is operated is set in a step S142.

  If “YES” in the step S138, the process proceeds to a step S143 to determine whether or not the C unit sensor 504 is ON. If NO in step S143, the process proceeds to step S6 to prohibit the operation. If “YES” in the step S143, the process proceeds to a step S144 to determine whether or not the head cover sensor 514 of the C head is ON. If NO in step S144, the C ID unit is correctly attached, so the C mode in which only the C ID unit operates is set. If “YES” in the step S144, it means that not all ID units are mounted, so the process proceeds to a step S6 to prohibit the operation.

  FIG. 15 shows the relationship between the LED head Y12 to which the head cover 601 is attached and the ID unit K4. Since the head cover 611 covers the LED head Y12, the floating toner 562, paper dust, and dust that are likely to be generated during a printing operation or the like only adhere to the surface of the head cover 611, so that important optical parts can be protected. At the same time, the sensor cover 611b and the head cover 611c face the surfaces of the reflective ID unit sensor and the head cover sensor, so that the LED head can be protected from the floating toner 562, paper dust, and dust. As described above, the head cover 611 can be easily removed by operating the latch. For example, the head cover 611 is attached if the Y ID unit is attached after removing the head cover attached to the Y position. Since the Y ID unit is detected, printing with two colors K and Y is possible. The same applies when the M or C ID unit is mounted.

  In addition, when adding an ID unit, the user determines whether to reset the operation mode setting or to execute a printing operation according to an instruction on the display unit.

  According to the second embodiment, since the mounting of the head cover and the ID unit can be individually determined from the output result of each sensor, the printing operation is prohibited according to the detection output of the sensor, or the mode at the time of monochromatic printing It is possible to switch the printing operation to one of the modes for full color printing. At the same time, an optical part such as an LED head part or an optical sensor can be protected.

  Although the LED type color printer has been described in the second embodiment, the present invention is not limited to this type. For example, a laser-type color printer using coherent light has an optical unit that forms an electrostatic latent image by irradiating light, and printing is possible without mounting all ID units. . The second embodiment can also be applied to an image forming apparatus having such a configuration.

Embodiment 3
When all ID units are installed, monochrome printing and color printing can be performed at different printing speeds. In monochrome printing, one color toner layer is transferred onto the paper, while in color printing, three color toner layers, that is, three toner layers are transferred. Since the thickness of the toner layer is different between monochrome printing and color printing, it is necessary to change the amount of heat applied to the toner layer by the fixing device in order to reliably melt and fix the toner.

  In the second embodiment, a uniform amount of heat is supplied to the toner layer at the time of fixing regardless of the number of ID units mounted. Therefore, a printing defect called hot offset may be caused. Embodiment 3 solves such a problem.

  FIG. 16 shows the main part of the control block according to the third embodiment. The overall configuration of the apparatus is the same as that of the second embodiment. In addition to the configuration of the second embodiment, the control unit 801 in FIG. 16 sets the printing speed when the one-color ID unit is attached to V2 and the printing speed when the two-color ID unit is attached to V2. A speed table 801c that satisfies V1> V2> V3> V4 is provided, where V3 is a printing speed when three color ID units are attached, and V4 is a printing speed when all ID units are attached. For example, V1 is a printing speed that matches the fixing temperature during single-color printing, and V4 is a printing speed that matches the fixing temperature during full-color printing. The operation mode setting unit 804 switches the operation mode to one of a single color operation mode, a two color operation mode, a three color operation mode, and a full color operation mode according to the number of installed ID units in addition to the print operation mode. And

  In addition to the state where the K ID unit shown in FIG. 3 is attached, a case where the head cover 611 at the Y position is removed and a Y ID unit is newly attached will be described.

  In FIG. 16, ID unit detection signals are output to the control unit 801 from the K sensor group 811 and the Y sensor group 812. A detection signal indicating that the ID unit is not attached and the head cover is attached is output from the M sensor group 813 and the C sensor group 814 to the control unit 801. It is assumed that the operation mode setting unit 804 is set in advance to the operation mode of only the K ID unit by the user.

  The control unit 801 receives detection signals from the sensor groups 811, 812, 813, and 814, and stores them in the detection result storage unit 801b. The comparison unit 801a compares the mode setting set by the operation mode setting unit with the detection signal stored in the detection result storage unit 801b. In this case, since they are different, they are displayed on the display unit 802. When the user issues a printing operation via the operation unit 803 in order to command two-color printing of K and Y, the control unit 801 switches the speed table 801c from V1 to V2, which is slower than V1, and operates in the operation mode. Commands the setting unit 804 to perform a printing operation. In addition, when the M ID unit is installed and the three-color printing operation is permitted, the M and C ID units are installed and the full-color printing operation is installed and the printing operation is permitted, or the M and C Similarly, the control unit 801 switches the speed from V3 to V4 that is slower than V3 even when the ID unit is attached and full-color printing operation is permitted.

  FIG. 17 is a table showing the relationship between the number of installed ID units and the printing speed, and is stored in the speed setting unit 801a in the control block of FIG. The printer according to the present invention switches the printing speed according to the number of ID units to be mounted. That is, when the number of ID units attached increases to 1, 2, 3, and 4, the printing speed is switched to V1, V2, V3, and V4. Here, the printing speed has a relationship of V1> V2> V3> V4. Further, since the head cover 611 is attached during the printing operation, not only the LED head but also the ID unit sensor and the head cover sensor can be protected from floating toner, paper dust and dust.

  According to the third embodiment, since the printing speed is changed according to the number of installed ID units, the user does not have to wait more than necessary.

  In the third embodiment, the LED type color printer has been described. However, the present invention is not limited to this type, and an optical unit to irradiate is provided, and even if all ID units are not attached, only the attached ID units can be used. The present invention can be applied to a color printer (for example, a laser system using coherent light) capable of printing a desired color. The speed table of the control unit is not limited to the relationship of V1> V2> V3> V4, but a speed table such as V1> V2 ≧ V3 ≧ V4, V1 ≧ V2> V3 ≧ V4, V1 ≧ V2 ≧ V3> V4, What is necessary is just to have each speed table corresponding to the number of ID units mounted, such as a speed table of V1> V2> V3 ≧ V4 and V1> V2 ≧ V3> V4. The third embodiment can be applied to an apparatus that operates at different printing speeds corresponding to the number of ID units to be mounted.

1 is a schematic view of an LED color printer according to the present invention. The state which opened the top cover of the LED color printer shown in FIG. It is a side view which shows the state in which only the ID unit of K was mounted | worn. It is an external view which shows a head cover. It is sectional drawing seen along the AA line of FIG. 4 shows another rotating body and toner supply roller according to the present invention showing the relationship between the Y LED head portion mounted on the head cover and the K ID unit. It is sectional drawing of an LED head part. 3 is a block diagram illustrating a control unit according to Embodiment 1. FIG. It is a side view which shows the apparatus of Embodiment 2. It is an external view which shows a head cover. FIG. 6 is a block diagram illustrating a control unit according to a second embodiment. 6 is a flowchart illustrating setting of an operation mode of the printer according to the present invention. Details of the subroutine of step S1 in FIG. 12 are shown. Details of the subroutine of step S1 in FIG. 12 are shown. The relationship between the LED head to which the head cover is attached and the ID unit is shown. 10 is a block diagram illustrating a control unit according to a third embodiment. 10 shows a speed table showing the relationship between the number of installed ID units and the printing speed according to the third embodiment.

Explanation of symbols

19 LED head (exposure section),
601 protective member,
501, 502, 503, 504 ID unit sensor (image forming unit detection means),
601 head cover,
601b sensor cover,
801 control unit (determination unit, wearing state determination unit),
801a comparison unit,
801c speed table,
804 operation mode setting section,
802 display unit,
803 operation unit,
811, 812, 813, 814 Sensor group.

Claims (17)

In an image forming apparatus for forming an image by detachably attaching a corresponding image forming unit to each of a plurality of image forming unit mounting portions,
An image forming function unit that is provided corresponding to each of the image forming unit mounting units and that forms an image together with the mounted image forming unit;
An image forming apparatus comprising: a covering member that covers the image forming function unit.   2. The image forming apparatus according to claim 1, wherein each of the image forming unit mounting portions includes an image forming unit detecting unit that detects the presence or absence of the corresponding image forming unit.   The image forming apparatus according to claim 2, wherein the image forming unit detection unit detects the covering member when the covering member is mounted.   The image forming apparatus according to claim 2, wherein the covering member is in a position so as to cover the image forming unit detection unit.   The image forming apparatus according to claim 1, wherein each of the image forming unit mounting portions includes a covering member detection unit that detects the presence or absence of the corresponding covering member. Each of the image forming unit mounting portions includes an image forming unit detecting unit that detects the presence / absence of the corresponding image forming unit, and a covering member detecting unit that detects the presence / absence of the corresponding covering member,
The image forming apparatus according to claim 1, wherein the covering member is detected by both the image forming unit detecting unit and the covering member detecting unit. Each of the plurality of image forming unit mounting portions includes an image forming unit detecting unit that detects the presence / absence of the corresponding image forming unit, and a covering member detecting unit that detects the presence / absence of the corresponding covering member,
Based on the detection result of the image forming unit detection means and the detection result of the covering member detection means, it is determined whether or not the image forming unit and the covering member are attached to the corresponding image forming unit attachment portion. The image forming apparatus according to claim 1, further comprising a determination unit that performs the determination.   The image forming apparatus according to claim 7, further comprising an operation mode setting unit that sets an operation mode of image formation based on a determination result of the determination unit.   The image forming function unit is an exposure unit that forms an electrostatic latent image on a photoconductor provided in the image forming unit, and the covering member covers a light exit port of the exposure unit. The image forming apparatus described.   The image forming apparatus according to claim 8, further comprising a display unit, wherein the display unit displays a determination result of the wearing state determination unit when the operation mode is set.   And further comprising an operation unit, and based on a command input via the operation unit, the mounting state determination unit determines whether to set an operation mode corresponding to the determination result of the mounting state determination unit The image forming apparatus according to claim 8.   9. The apparatus according to claim 8, wherein when the mounting state determination unit determines that no image forming unit is mounted on the image forming unit mounting unit, the mounting state determination unit prohibits an image forming operation. Image forming apparatus.   When the mounting state determination unit determines that either the image forming unit or the covering member is not mounted on at least one image forming unit mounting unit, the mounting state determination unit performs an image forming operation. The image forming apparatus according to claim 8, wherein the image forming apparatus is prohibited.   9. The image according to claim 8, further comprising a comparison unit that compares a determination result of the mounting state determination unit with a mounting unit of an image forming unit corresponding to an operation mode preset by the operation mode setting unit. Forming equipment.   The image forming apparatus according to claim 13, further comprising a display unit that displays a comparison result by the comparison unit.   If the comparison result by the comparison unit does not match, the wearing state determination unit determines whether to set the operation mode based on a command input via the operation unit. The image forming apparatus according to claim 14. A speed control unit for controlling the operation speed of image formation;
The image forming apparatus according to claim 8, wherein the speed control unit determines an image forming speed according to the number of mounted image forming units determined by the mounting state determining unit.

Images