Image formation device

Abstract

To solve such a problem that productivity declines if a printing operation is always stopped until a medium is finalized when the medium cannot be determined on the basis of characteristics of a paper detected by a medium sensor.SOLUTION: An image formation device controls an image formation operation as a medium closest to characteristics detected by a medium sensor in a printing mode prioritizing productivity when the medium cannot be determined, and presents a medium candidate from the characteristics detected by the medium sensor in a printing mode prioritizing an image quality, and controls the image formation operation by the selected medium.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus having a media detection sensor disposed on a recording paper transport path for determining characteristics such as the surface property and thickness of the recording paper. [Background technology]

[0002] Conventionally, in image forming devices equipped with a media sensor for detecting the characteristics of paper on the paper transport path, the media is judged from the characteristics of the paper detected by the media sensor, and the operating conditions of the image forming operation, such as the paper transport speed, developing / transfer output, and fixing temperature, are determined to form optimal images.

[0003] However, when it is not possible to determine the media due to the characteristics of the paper detected by the media sensor, a device has been devised that determines the media and resumes printing by temporarily suspending the paper and then querying the controller or by having the user select the media. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-009363 A Summary of the Invention [Problem to be solved by the invention]

[0005] When the media cannot be determined based on the characteristics of the paper detected by the media sensor, productivity decreases if the printing operation is always stopped until the media is determined.

[0006] The present invention has been made in consideration of the above problems, and aims to provide an image forming device that not only prevents a decrease in productivity even when the media cannot be determined, but also prints on appropriate media to prevent a decrease in the quality of the finished product. [Means for solving the problem]

[0007] In order to solve the above problems, the image forming apparatus of the present invention comprises an operation means capable of inputting information, a paper feeding means for storing paper, an image forming means for forming an image on paper transported from the paper feeding means, a detection means for detecting the characteristics of the paper transported from the paper feeding means, a print mode setting means for selecting a first control mode in which printing control on the paper is performed with priority given to productivity of the finished product, and a second control mode in which printing control is performed with priority given to image quality of the finished product, and a media determination means for determining a media from data obtained from the detection means, and is characterized in that if the media determination means is unable to determine a media, in the first control mode the printing operation is controlled using the media that is closest to the data obtained from the detection means, and in the second control mode the printing operation is controlled using the media selected by the user by the operation means. Effect of the Invention

[0008] As described above, according to the present invention, when the media cannot be determined based on the paper characteristics detected by the media sensor, a decrease in productivity and quality of the finished product can be prevented by switching between printing with the closest media or allowing the user to select the media depending on the print mode. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a cross-sectional view of the image forming apparatus. [Diagram 2] FIG. 1 is a block diagram of an image forming system. [Diagram 3] FIG. 2 is a cross-sectional view of the media sensor. [Figure 4] 13 is a media determination flowchart. [Diagram 5] FIG. 1 is a diagram showing the relationship between detection data and media. [Figure 6] FIG. [Figure 7] FIG. 13 is a diagram showing a print mode selection screen. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the embodiment described below is an example, and the present invention is not limited to the following embodiment. EXAMPLES

[0011] (Basic configuration) Fig. 1 is a cross-sectional view of an image forming apparatus 100 and a scanner unit 101 according to an embodiment of the present invention, and Fig. 2 is a control block diagram according to the embodiment of the present invention. The basic configuration will be described with reference to Figs. 1 and 2.

[0012] The control unit 300 in FIG. 2 is composed of a CPU 301, a ROM 302, a RAM 303, and an EEPROM 304. When an instruction to start a print operation (hereinafter, a job) is input to the CPU 301 from the UI 330 of the operation unit, for example, the print operation is started. The CPU 301 is configured to be able to drive and control the pre-fixing conveyance motor 145, the fixing motor 173, the post-fixing conveyance motor 146, the discharge conveyance 1 motor 148, and the discharge conveyance 2 motor 149, which are connected via an I / O 307. Also, the CPU 301 is capable of detecting input signals from the paper conveyance sensor 171, the pre-register conveyance sensor 160, the paper feed pickup sensor 152, the media sensor 280, and the like, also via the I / O 307. Furthermore, the CPU 301 is configured to be able to accept jobs input from a network I / F 314 and a fax I / F 315.

[0013] The CPU 301 also has an image processing unit 316 that processes images corresponding to jobs from the UI 330 and the like, and performs image processing such as image development and rotation. The CPU 301 is configured to be able to control an image forming unit 320. The image forming unit 320 can control high voltages and drives of the process unit 120, transfer belt 130, secondary transfer unit 140, and the like in FIG. 1, and can also control the laser scanner unit 110. The image forming unit 320 can also control the heater of the fixing unit 170 in FIG. 1. The scanner unit 101 is a unit that reads an original when making a copy.

[0014] (Explanation of Image Forming Operation) Next, the basic image forming operation will be described with reference to Figures 1 and 2. When a job is input from the UI 330, the CPU 301 interprets the job and starts the print operation. The CPU 301 drives the pre-fixing transport motor 145, which serves as the drive source for the paper feed pickup roller 151, via the I / O 307, which causes the paper feed pickup roller 151 to rotate and feed and transport the sheets in the paper feed cassette 150 one by one. At this time, the CPU 301 uses the paper feed pickup sensor 152 to monitor whether the paper feed operation has been performed normally.

[0015] Next, media detection will be described. The thickness and surface properties of the transported paper are detected by a media sensor 280 arranged on the transport path, and printing conditions such as fixing temperature and transfer voltage and image formation are performed according to the detected properties. The media sensor 280 will be described later.

[0016] Meanwhile, the CPU 301 starts the image forming operation in the process unit 120 so as to be in time for the arrival of the paper at the secondary transfer section 140. The process unit 120 is composed of a photosensitive drum, a developing device, a charging roller, a photosensitive drum cleaner, and the like. In the process unit 120, after the surface of the photosensitive drum is charged, a latent image is formed on the photosensitive drum by a laser irradiated from the laser scanner unit 110. Then, the formed latent image is developed on the photosensitive drum by the toner in the developing device. Then, a primary transfer voltage is applied to the toner image developed on the photosensitive drum in the primary transfer section 121, and the toner image is transferred to the transfer belt 130. The toner image transferred to the transfer belt 130 reaches the secondary transfer section 140 by the rotation of the transfer belt 130.

[0017] Furthermore, CPU 301 detects the position of the paper conveyed by conveyance rollers A 153, B 154, and C 155 by monitoring pre-registration conveyance sensor 160. Then, taking into consideration the timing when the leading edge of the paper reaches pre-registration conveyance sensor 160, conveyance of the paper is controlled so that the leading edge of the paper and the leading edge of the toner image on transfer belt 130 coincide at secondary transfer unit 140. For example, if the paper arrives earlier than the toner image, pre-registration conveyance rollers 161 stop the paper for a predetermined time and then resume conveyance.

[0018] By applying a secondary transfer voltage to the paper and toner image that have reached secondary transfer unit 140 in the manner described above, the toner image is transferred onto the paper.

[0019] After the secondary transfer, the paper is conveyed to a conveyor belt 190 and a fixing device 170. The toner image on the paper is heated and fixed to the paper by the fixing device 170. After that, the paper is conveyed further downstream of the apparatus.

[0020] When the leading edge of the paper after fixing reaches the paper transport sensor 171, the CPU 301 determines whether the paper should be transported to paper transport path A230 or paper transport path B231 according to the job contents specified in advance from the UI 330, and switches the transport destination of the paper by switching the transport flapper 172. Specifically, in the case of a double-sided print job, the transport flapper 172 is switched to transport the paper to paper transport path A230, and in the case of single-sided or double-sided printing, when the paper is to be discharged to the paper output tray 196 or paper output tray 199, the transport flapper 172 is switched and the paper is transported to paper transport path B231.

[0021] The paper conveyed to paper conveying path B231 is conveyed further downstream by conveying rollers D162 and E232. The paper is conveyed by discharge rollers A241, B242, and C243 driven by discharge conveying motor 148, and when there is a command to discharge the paper to discharge tray 196, conveying flapper 183 is switched to output the paper to discharge tray 196. When there is a command to discharge the paper to discharge tray 199, conveying flapper 183 is switched. Then, the paper is conveyed by discharge rollers D244, E245, and F246 driven by discharge conveying motor 2 149, and output to discharge tray 199.

[0022] During double-sided printing, detailed description will be omitted, but the paper conveyed to paper conveying path A 230 is guided to conveying rollers C 155. Thereafter, the paper on which the image on the back side has been formed is conveyed to paper conveying path B 231 and output to paper output tray 196 or paper output tray 199. When the entire job is completed, CPU 301 displays the completion on UI 330.

[0023] The above-described basic image forming operation is merely an example, and the present invention is not limited to the above-described configuration.

[0024] (Explanation of media detection by media sensor) Fig. 3 is a cross-sectional view of the media sensor 280. Next, how the thickness and surface properties of the paper are detected will be described with reference to Fig. 3.

[0025] The media sensor 280 is composed of the media sensor main unit 54 and an external LED 55b as external illumination means. The media sensor main unit 54 has therein an LED 55a as illumination means, a phototransistor 56a as first reading means, and a phototransistor 56b as second reading means.

[0026] Next, detection of the surface property of the paper will be described. Light from LED 55a as a light source is irradiated through slit 57a onto the surface of sheet P, which is paper on paper transport guide 40. Also, paper transport guide 40 is provided with a window for irradiating light from the back side of sheet P. Light reflected from sheet P is collected through slits 57b and 57c and received by phototransistors 56a and 56b. For light from LED 55a as a light source, phototransistor 56a obtains a diffuse reflection output value, and phototransistor 56b obtains a regular reflection output value.

[0027] From the obtained output value, the surface roughness x is calculated by the following formula. Surface roughness x = specular reflection power / diffuse reflection power (Equation 1)

[0028] The calculation formula of Equation 1 utilizes the characteristics that a surface is "smooth" and "fine" and easily reflects specularly. An arithmetic device (not shown) disposed in the media sensor 280 performs the calculation of Equation 1 to quantify the surface property of the sheet P and notify the CPU 301 of the calculation result. The CPU 301 judges the surface property using the notified numerical value of the surface property and a threshold value for judging the surface property. If the value is higher than the threshold value, the surface property is judged to be "smooth" and "fine", and if the value is lower than the threshold value, the surface property is judged to be "rough" and "coarse". Although one threshold value is used in this embodiment, multiple threshold values ​​may be used to make further finer divisions.

[0029] Next, detection of the thickness of the paper will be described. Light emitted from the external LED 55b as a light source is irradiated onto the rear surface of the sheet P through a light collecting guide 57d that is provided to collect the light. The transmitted light from the sheet P is received by the phototransistor 56a through the slit 57b. The phototransistor 56a obtains a regular transmission output value for the light emitted from the external LED 55b as a light source. This detects the transmittance of the sheet P. The thicker the paper, the lower the transmittance, and the thinner the paper, the higher the transmittance. Taking advantage of this characteristic, the thickness of the paper is determined using the transmittance. The detected transmittance is notified to the CPU 301. The CPU 301 determines the thickness using the notified transmittance value and a threshold value for determining the thickness.

[0030] The CPU 301 determines the media to be used for printing from the surface property x and transmittance detected by the media sensor 280, and operates to perform optimal control in the subsequent image forming operation.

[0031] In this embodiment, an optical sensor is used, but this is not limited to this, and a configuration using another type of sensor, such as an ultrasonic sensor, may be used as long as the sensor is capable of detecting surface properties or thickness.

[0032] Furthermore, in this embodiment, the media is determined from data on the thickness and surface properties of the paper, but this is not limiting, and other data may be detected to determine the media.

[0033] (Print mode selection explanation) 7 is a diagram showing a print mode selection screen. The print modes will be described with reference to FIG.

[0034] 7, the user can select the print mode as either a "productivity priority mode" or a "image quality priority mode" via the UI 330. When the CPU 301 receives print mode information from the UI 330, it stores it in the RAM 303 and uses it to determine the image formation operation.

[0035] In this embodiment, the "productivity priority mode" achieves high productivity of the finished product by having the CPU 301 control the image forming unit 320 to perform high-speed control of the process unit 120, the transfer belt 130, the secondary transfer unit 140, the laser scanner unit 110, and paper transport.

[0036] On the other hand, in the "image quality priority mode", the CPU 301 controls the image forming unit 320 to perform low-speed control of the process unit 120, transfer belt 130, secondary transfer unit 140, laser scanner unit 110 and paper transport, thereby achieving high image quality in the finished product.

[0037] (Explanation of how media is determined by print mode) Next, a method of determining media depending on a print mode will be described with reference to the flowchart of determining media depending on a print mode in FIG. 4, the relationship between detected data and media in FIG. 5, and the media selection screen in FIG.

[0038] In step S1000, the CPU 301 drives the pre-fixing transport motor 145 to start transporting paper from the paper feed cassette 150, and the process proceeds to step S1001.

[0039] In S1001, the CPU 301 determines whether the paper has reached the position of the media sensor 280 based on an input signal from the pre-registration transport sensor 160. If the pre-registration transport sensor detects the paper, the CPU 301 determines that the paper has reached the media sensor 280 and proceeds to S1002.

[0040] In S1002, CPU 301 acquires data on multiple points on the paper using media sensor 280, and determines the media from the acquired data. Figure 5 shows an example of media determination. In Figure 5(a), the data range for surface property x and transmittance is within the threshold for plain paper 2, so CPU 301 determines the media to be plain paper 2. In Figure 5(b), the data range for surface property x and transmittance straddles the thresholds for coated paper 2 and plain paper 2, and plain paper 2 and plain paper 1, respectively, so CPU 301 determines the media to be unknown. Once the media has been determined, CPU 301 proceeds to S1003. If the media is determined to be a unique media and not an unknown media, the process proceeds to S1008, and if the media is determined to be unknown, the process proceeds to S1004.

[0041] In S1004, the CPU 301 determines whether the print mode stored in the RAM 303 is the "productivity priority mode." If the CPU 301 determines that it is the "productivity priority mode," the process proceeds to S1005, and if it determines that it is the "image quality priority mode," the process proceeds to S1006.

[0042] In S1005, CPU 301 determines the media to be used in the image forming operation that has the most similar characteristics from the data acquired by media sensor 280 in S1002. For example, in the data in Fig. 5B, the surface property x is closer to that of coated paper, and the transmittance is closer to that of plain paper 2. From this, CPU 301 determines that the media with the most similar characteristics is coated paper 2. After CPU 301 determines the media to be used in the image forming operation, the process proceeds to S1008.

[0043] In S1006, the CPU 301 displays a media selection screen on the UI 330. The media selection screen displays a soft switch that allows the user to select candidate media from the data acquired by the media sensor 280 in S1002. For example, if data such as that shown in FIG. 5(b) is acquired, the candidate media "Plain Paper 1," "Plain Paper 2," "Coated Paper 1," and "Coated Paper 2" are displayed as shown in FIG. 6 to allow the user to select. At this time, if no suitable media is displayed as a candidate, the user can make a more detailed media selection by pressing the "Other" soft switch. After the CPU 301 displays the media selection screen, the process proceeds to S1007.

[0044] In S1007, the CPU 301 receives information about the medium selected by the user from the UI 330 and determines the medium to be used in the image forming operation.Then, the CPU 301 proceeds to S1008.

[0045] In S1008, the CPU 301 executes the image forming operation described above with the determined medium, and continues the operation until it is determined in S1009 that it is the final page, and ends the operation when it is determined that it is the final page.

[0046] As described above, according to this embodiment, when the printing mode is "productivity priority mode," for paper whose media cannot be determined by the media sensor 280, it is determined that the paper is the one with the closest characteristics, and image formation operation is continued without interruption, thereby preventing a decrease in productivity.

[0047] On the other hand, when the print mode is the "image quality priority mode," the image forming operation is stopped and the user is allowed to select the media, thereby enabling the optimal image forming operation to be performed, thereby making it possible to obtain a high-quality output. [Explanation of symbols]

[0048] 100 Printers 110 Laser Scanner 120 Process Unit 130 Intermediate transfer belt 150 Paper feed cassette 151 Paper feed pickup roller 160 Front register transport sensor 170 Fixing unit 280 Media Sensor 301 CPU 302 ROM 303 RAM 330 UI

Claims

1. An operating means capable of displaying and inputting information; A paper feed means for storing paper; an image forming means for forming an image on the paper conveyed from the paper feeding means; a detection means for detecting a characteristic of the paper conveyed from the paper feeding means; a print mode setting means for selecting a first control mode for controlling printing on the paper, which prioritizes productivity of the finished product, and a second control mode for controlling printing on the paper, which prioritizes image quality of the finished product; a media determination means for determining a media from the data acquired from the detection means, An image forming apparatus characterized in that, if the media determination means is unable to determine the media, in a first control mode, the printing operation is controlled using the media that is closest based on the data obtained from the detection means, and in a second control mode, the printing operation is controlled using the media selected by the user via the operation means.

2. 2. The image forming apparatus according to claim 1, wherein when a second mode is selected by the print mode setting means and the media determination means is unable to determine the media, a plurality of media candidates matching the paper characteristics detected by the detection means are presented to the operation means.

Images