JP2007108569A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of making automatic paper type detection and automatic setting function of printing conditions to be more stabilizing, and of outputting stable image quality. <P>SOLUTION: The image forming apparatus 101 is equipped with a reflection type optical sensor 701 which can set information relating to the characteristics of a recording material and an apparatus control means 702, which can automatically set printing conditions based on the results of the measurement. The image forming apparatus has a correspondence control means, capable of arbitrarily setting the correspondence of the information related to the characteristics of the recording material measured by the reflection-type optical sensor 701 and the printing conditions to be set at printing. The means is capable of acquiring information from an information management means 703, which can be called from the outside and setting the correspondence of the information related to the characteristics of the recording material. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine or a laser printer having a function of controlling printing conditions based on a result of a reflective optical sensor that detects reflected light of a recording material.

  Image forming apparatuses such as copying machines and laser printers include a latent image carrier that carries a latent image, and a developing device that visualizes the latent image as a developer image by applying a developer to the latent image carrier. ing. Further, a transfer unit that transfers the developer image by the developing device to the recording material to be conveyed, and the recording material that has received the transfer of the developer image by the unit is heated and pressed under predetermined fixing processing conditions. Accordingly, a fixing device for fixing the developer image is provided.

  Conventionally, in such an image forming apparatus, for example, the size and type (hereinafter, also referred to as a paper type) of a print sheet as a recording material is set by a user on a display panel or the like as an operation unit provided in the main body of the image forming apparatus. . Then, control is performed so as to set the fixing process conditions (for example, the fixing temperature and the conveyance speed of the recording material passing through the fixing device) according to the setting.

  Alternatively, a development condition, a transfer condition, a conveyance condition, or a fixing condition are variably controlled according to the type of the recording material by using a sensor for determining the recording material in the image forming apparatus.

  In particular, in the latter image forming apparatus, for example, as proposed in Patent Document 1, a light emitting element is provided, and light emitted from the light emitting element is reflected by the detection surface. In some cases, a reflective optical sensor including a first light receiving sensor installed at a position for receiving the reflected light and a second light receiving sensor installed at an angle different from the light receiving sensor is installed. . In such a sensor, for example, the glossiness can be identified as a characteristic of the recording material, and a gloss film having a high glossiness and plain paper having a low glossiness can be distinguished.

In addition, for example, in Patent Document 2, a surface image of a recording material is picked up by a CCD sensor or a CMOS sensor and the roughness of the recording material is detected from the magnitude relationship of the light, A method for detecting the thickness of the recording material from the length has been proposed.
Japanese Patent Laid-Open No. 2-138805 JP 2002-182518 A

  However, image forming apparatuses such as Patent Document 1 and Patent Document 2 have the following problems.

  Since there are many types of recording materials in the market, it is very difficult to accurately detect all types of recording materials in the market and determine appropriate printing conditions for all types. In addition, there is a problem that a new type of printing paper is released after the release of the printer, and the accurate printing conditions are not automatically set for the new type of printing paper.

  The present invention has been made paying attention to the above points. An image forming apparatus capable of further stabilizing automatic paper type detection and automatic setting of printing conditions and outputting an image with stable image quality. It is intended to provide.

  In order to achieve the above object, the present invention has the following configuration.

In an image forming apparatus comprising a reflection type optical sensor capable of measuring information relating to characteristics of a recording material, and an apparatus control means capable of automatically setting printing conditions based on the measurement result,
Corresponding setting means that can arbitrarily set the correspondence between the information about the characteristics of the recording material measured by the reflective optical sensor and the printing conditions set at the time of printing, the means is an information management means that can be called from the outside An image forming apparatus characterized in that the information can be acquired from the information and the correspondence between the information relating to the characteristics of the recording material and the printing conditions can be set.

  As described above, according to the invention of the present application, the automatic paper type detection and print condition automatic setting functions can be further stabilized, and an image can be output with stable image quality.

  In addition, it is possible to realize automatic setting of appropriate printing conditions corresponding to various situations such as the latest market situation of printing paper and the latest recommended manufacturer setting conditions.

  In addition, the same settings can be shared by multiple printers, and it is possible to perform stable automatic determination stably in multiple printers, so that it is possible to achieve stable high-quality printing. Can do.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to examples.

  FIG. 2 is a schematic cross-sectional view showing a schematic configuration of a reflective optical sensor for detecting the surface property of a recording material.

  As shown in FIG. 2, the sensor unit 123 includes an LED 1111 that is light irradiation means mounted obliquely (however, the light source is not an LED, but may be a xenon tube or a halogen lamp, for example). The first phototransistor 1112 (the light receiving element may be a photodiode, a CCD, or a CMOS sensor). Furthermore, it has a second phototransistor 1113 (the light receiving element may be a photodiode, a CCD or a CMOS sensor, or only the first sensor). At this time, the LED 1111 is mounted obliquely with respect to the detection surface as shown in FIG. However, you may irradiate diagonally with the light guide which is not shown in figure, without mounting LED diagonally.

  The sensor unit 123 is configured to maintain a certain distance from the detection surface by an intermediate member such as a roller 1116, for example. At this time, even if there is no intermediate member such as a roller, the detection surface and the sensor unit may be kept at a certain distance, or the detection surface may be within the detectable range of the sensor.

  The second phototransistor 1113 is preferably in the opposite direction of the LED at the same angle as the LED incident angle α °.

  The first phototransistor 1112 is preferably on the same side as the LED or at a location away from the incident angle of the LED. In the embodiment of FIG. 2, the incident angle of the first phototransistor 1112 is 0 °.

  Light using the LED 1111 as a light source is applied to the surface of the recording material 1114. Regular reflection light and diffuse reflection light from the recording material 1114 are incident on the second phototransistor 1113 and the first phototransistor 1112, respectively. Thereafter, the ratio between the output of the second phototransistor 1113 and the output of the first phototransistor 1112 is calculated, and surface property information is read as information relating to the characteristics of the recording material. Among OHT, gloss paper, and plain paper, OHT has the highest glossiness and the lowest ratio of diffuse reflection light to regular reflection light. Next, the ratio of diffuse reflection light to glossy paper, plain paper, and regular reflection light increases. The paper type is determined based on the calculation result.

  FIG. 3 is a diagram illustrating a configuration of the image forming apparatus.

  In the figure, 101 is an image forming apparatus, 102 is a paper cassette, 103 is a paper feed roller, 104 is a transfer belt drive roller, 105 is a transfer belt, and 106 to 109 are yellow, magenta, cyan, and black photosensitive drums. 110 to 113 are transfer rollers, 114 to 117 are yellow, magenta, cyan, and black cartridges, 118 to 121 are yellow, magenta, cyan, and black optical units, and 122 is a fixing unit.

  The image forming apparatus transfers an image of yellow, magenta, cyan, and black on a recording material by using an electrophotographic process, and heat-fixes the toner image with a fixing roller based on temperature control.

  Further, each color optical unit is configured to form a latent image by exposing and scanning the surface of each photosensitive drum with a laser beam, and a series of image forming operations is performed so that an image can be obtained from a predetermined position on the recording material to be conveyed. In order to be transferred, scanning control is performed in synchronization.

  Further, the image forming apparatus includes a paper feed motor that feeds and conveys printing paper as a recording material, a transfer belt drive motor that drives a transfer belt drive roller, a photosensitive drum drive motor that drives each color photosensitive drum and a transfer roller, and a fixing roller. A fixing drive motor is provided.

  A paper type detection sensor unit 123 measures the glossiness of the surface of the paper in the cassette or the surface of a cassette plate (not shown).

  A control CPU (not shown) provided in the image forming apparatus fuses and fixes the toner image on the recording material by applying a desired amount of heat to the recording material by the fixing unit 122.

  Next, the operation of the control CPU will be described with reference to FIG.

  FIG. 4 is a diagram showing the configuration of each unit controlled by the control CPU.

  In the figure, 10 is a CPU, 11 is a paper type detection sensor, 12 to 15 are equipped with polygon mirrors, motors and lasers, and an optical unit for scanning a laser on the photosensitive drum surface to draw a desired latent image, 16 It is a paper feed motor for transporting a recording material. 17 is a paper feed solenoid used to start driving of a paper feed roller for feeding a recording material, and 19 is a high voltage power source for controlling primary charging, development, primary transfer, and secondary transfer bias necessary for the electrophotographic process. , 20 is a drum drive motor for driving the photosensitive drum and the transfer roller. Reference numeral 21 denotes a belt drive motor for driving the transfer belt and the rollers of the fixing unit. Reference numeral 22 denotes a fixing unit. The control CPU monitors the temperature with a thermistor (not shown) and controls to keep the fixing temperature constant.

  Reference numeral 23 denotes an ASIC that performs motor speed control inside the paper type detection sensor 11 and the optical units 12 to 15 and speed control of the paper feed motor based on instructions from the CPU 10.

  The motor speed control is performed by detecting a tack signal from a motor (not shown) and outputting an acceleration or deceleration signal to the motor so that the interval between the tack signals becomes a predetermined time. For this reason, it is more advantageous that the control circuit is composed of a hardware circuit of the ASIC 23 to reduce the control load on the CPU 10.

  At a predetermined timing for detection by the paper type detection sensor, the LED is turned on from the CPU 10 or the output port of the ASIC 23. The output MSSR of the second phototransistor 1113 and the output MSDR of the first phototransistor 1112 are input to the AD port of the CPU 10 or ASIC 23, and the amount of light received by the CPU 10 or ASIC23 phototransistor is recognized. Thereafter, based on the control flow described later, the type of the medium is determined from the ratio of the regular reflection light and the diffuse reflection light, and each calculation result is stored in the CPU 10 or a register in the ASIC 23. If the amount of light received at this time is extremely low, it is determined that the cassette is not set normally or the LED is broken.

  When the CPU 10 receives a print command in response to an instruction from a host computer (not shown), the paper type detection sensor 11 determines the presence / absence of a recording material and the state of the cassette, and if there is paper, the paper feed motor 16 and the drum drive motor 20. The belt drive motor 21 is driven. At the same time, the paper feed solenoid 17 is driven to transport the recording material to a predetermined position. The CPU 10 reads the register in the ASIC 23, determines the type of the fed recording material, and variably controls the developing bias condition of the high voltage power source 19 according to the result.

  For example, in the case of so-called rough paper where the surface fibers of the recording material are rough, control is performed to prevent toner scattering by lowering the developing bias than plain paper and suppressing the amount of toner adhering to the surface of the recording material. This is because the amount of toner adhering to the surface of the recording material is large especially in the case of rough paper, so that the problem that the image quality deteriorates due to the scattering of the toner due to the paper fibers is solved.

  Further, the CPU 10 determines the type of the fed recording material, and variably controls the temperature condition of the fixing unit 22 according to the result.

  This is effective particularly in the case of OHT, when the fixing property of the toner adhering to the surface of the recording material is poor, the OHT permeability is deteriorated.

  Further, the CPU 10 determines the type of the fed recording material, and variably controls the recording material conveyance speed according to the result. The variable control of the conveyance speed is realized by the CPU 10 setting the speed control register value of the ASIC 23 that controls the speed control.

  For example, with respect to a transmissive recording material such as OHT, the fixing temperature is raised and controlled in order to increase the permeability by changing the fixing temperature condition. Alternatively, the recording material conveyance speed may be changed and controlled depending on whether the type of the recording material is a transmissive type.

  Alternatively, in the case of glossy paper or the like, it is possible to improve the image quality by improving the fixability of the toner adhering to the surface of the recording material and increasing the gloss.

  FIG. 5 shows a control flow of state detection.

  At a predetermined timing, the CPU or ASIC starts detection and turns on the LED. Thereafter, the CPU or ASIC captures the output from the first phototransistor and also captures the output from the second phototransistor (in this case, the order of capturing the first and second phototransistors may be reversed). Subsequently, the ratio of the amount of light received by the second phototransistor to the amount of light received by the first phototransistor is calculated. The ratio indicates a value according to the glossiness. Thereafter, the paper type is determined by a calculation method described later. Subsequently, the print mode is set based on the determination result. Thereafter, after the LED is turned off, the detection is finished and the system waits for the next detection timing.

Next, the calculation method will be described. FIG. 6 shows a graph showing the result of calculating the ratio of the light reception amount of the second phototransistor to the light reception amount of the first phototransistor. When the calculation result is lower than the threshold value 6-1, it is determined that the paper is normal paper (Normal), and when it is a value between the threshold value 6-1 and the threshold value 6-2, it is determined that the paper is Gloss paper. . If the threshold is 6-2 or more, it is determined as OHT. The paper type can be discriminated by the above method.
In the present embodiment, the configuration for reading the surface property information as the characteristics of the recording material has been described. However, the present invention is not limited to this, and as a characteristic of the recording material, a thick paper or a thin paper can be detected as the recording material by installing a transmitted light detection LED (not shown) for the thickness of the recording material. Note that the LED for detecting transmitted light is disposed at a position facing the first phototransistor 1112 and the second phototransistor 1113 with the recording material interposed therebetween.

  FIG. 1 is a graph showing the ratio of the amount of light received by the second phototransistor to the amount of light received by the first phototransistor for eight types of paper.

  During the measurement, the sensor detection results vary. There are various factors such as variations in the surface properties of paper, variations among sensors, variations due to sensor mounting accuracy, and the like.

  Therefore, when threshold values are set so as to discriminate all paper types with a higher probability, the threshold values become threshold values 1-1 and 2-1 at the positions of the solid lines in FIG. 1, and “Normal2” and “Gloss3” ", There is a risk of misjudgment from time to time.

  At this time, when there is a user who does not use the paper types of “Normal 2” and “Gloss 3” surrounded by an ellipse, the threshold value 1-1 and the threshold value 2-1 are changed to the dotted threshold value 1-2 and the threshold value 2-2. As a result, no erroneous determination occurs and stable control is performed.

  The threshold is set to a position where the paper can be reliably discriminated by manually setting frequently used paper types in the printer device control means, or by setting frequently used paper in the printer and executing the calibration mode. This is done by automatically adjusting the threshold.

  As described above, in this embodiment, the surface property of the recording material is detected by the paper type detection sensor. Based on the result, the CPU or ASIC determines the developing condition of the high voltage power source, the control temperature condition of the fixing unit, or the conveying speed of the recording material. Automatic variable control. And about the paper type which a user uses, the structure which can be set as the setting which improves the detection accuracy preferentially is taken.

  Since the operation content of the image forming apparatus is the same as that of the first embodiment, the same reference numerals are used for the same parts as in the first embodiment, and the description is omitted by using the same reference numerals. Only the management means will be described.

  FIG. 7 is a schematic configuration diagram of this embodiment. In the image forming apparatus 101, a reflective optical sensor 701 is installed at a position where print paper can be detected, and is connected to the apparatus control unit 702. Further, the information management unit 703 shown in FIG. 7 can communicate with the apparatus control unit 702 in the image forming apparatus 101, and the apparatus control unit 702 can obtain information from at least the information management unit 703.

  The image forming apparatus 101 can obtain the latest print paper information and print condition setting data information set based on the information from the information management unit 703, and can update the information at an arbitrary timing. it can.

  In addition, it is possible to set the printing conditions of other image forming apparatuses 101 under the same conditions through the information management unit 703 and the printing conditions based on the paper type and surface property information set in one image forming apparatus. It has become.

  Since the operation content of the image forming apparatus is the same as that of the first embodiment, the same reference numerals are used to denote the same parts as those in the first embodiment, and the description thereof is omitted, and the printing is different from that in the first embodiment. Only the condition setting method will be described.

  In the present embodiment, even when a paper type having a high use frequency is selected, a description will be given of control in a case where an overlapping region occurs in the detection result and an erroneous determination occurs in either one.

  FIG. 8 shows a graph showing the detection results of two types of plain paper and one type of glossy paper.

  If the user uses only the paper types “Normal1” and “Gloss1”, the threshold is set to the threshold 8-1. If there is a possibility that the user uses paper types of “Normal 1”, “Normal 2”, and “Gloss 1”, the priority can be set by the user. For example, a comment that allows the user to set the priority order is displayed on the screen of the PC connected to the apparatus as shown in FIG. 9 to allow the user to set the priority order. Alternatively, the setting may be performed on a display panel as an operation unit provided in the apparatus.

  When the user selects “Gloss1”, the threshold value is set to the threshold value 8-2. Thereby, “Gloss1” can be detected with certainty, conditions for printing “Gloss1” stably can be automatically set, and the optimum image quality can be printed. Conversely, when “Normal2” is selected, the threshold is set to 8-3.

  By adopting a configuration that allows the selection as described above, it is possible to realize a printer that can reliably detect the paper type that the user wants to prioritize and print stably.

It is a graph which concerns on Example 1 of this invention. It is a schematic cross section of the reflective optical sensor according to Example 1 of the present invention. 1 is a schematic cross-sectional view illustrating an image forming apparatus according to Embodiment 1 of the present invention. 1 is a block diagram illustrating a configuration of an image forming apparatus according to Embodiment 1 of the present invention. It is a flowchart which shows the control flow which concerns on Example 1 of this invention. It is a graph which shows the paper type discrimination | determination result which concerns on Example 1 of this invention. It is a figure which shows schematic structure which concerns on Example 2 of this invention. It is a graph which shows the paper type discrimination | determination result which concerns on Example 3 of this invention. It is a figure which shows schematic structure which concerns on Example 3 of this invention.

Explanation of symbols

123 Sensor unit (supports reflective optical sensors)
1111 LED (corresponding to reflective optical sensor)
1112 First phototransistor (corresponding to a reflective optical sensor)
1113 Second phototransistor (corresponding to reflection type optical sensor)
1114 Recording material 1116 Roller (corresponding to reflection type optical sensor)
DESCRIPTION OF SYMBOLS 101 Image forming apparatus 102 Paper cassette 103 Paper feed roller 104 Transfer belt drive roller 105 Transfer belt 106-109 Photosensitive drum 110-113 Transfer roller 114-117 Cartridge 118-121 Optical unit 122 Fixing unit 10 CPU (Corresponding setting means)
11 Paper type detection sensor (corresponding to reflective optical sensor)
16 Feed motor 17 Feed solenoid 19 High-voltage power supply 20 Drum drive motor 21 Belt drive motor 22 Fixing unit 23 ASIC (corresponding to correspondence setting means)
701 Reflective optical sensor 702 Device control means 703 Information management means

Claims (6)

In an image forming apparatus comprising a reflection type optical sensor capable of measuring information relating to characteristics of a recording material, and an apparatus control means capable of automatically setting printing conditions based on the measurement result,
Corresponding setting means that can arbitrarily set the correspondence between the information about the characteristics of the recording material measured by the reflective optical sensor and the printing conditions set at the time of printing, the means is an information management means that can be called from the outside An image forming apparatus characterized in that the information can be acquired from the information and the correspondence between the information relating to the characteristics of the recording material and the printing conditions can be set.   The image forming apparatus according to claim 1, further comprising: a unit that can share the correspondence between the information regarding the characteristics of the recording material set by the correspondence setting unit and the printing condition among a plurality of image forming apparatuses.   The correspondence setting means includes a means for setting correspondence between the information on the characteristics of the recording material and the printing condition from an operation unit of the image forming apparatus, and the correspondence can be shared by a plurality of image forming apparatuses. The image forming apparatus according to claim 1.   The correspondence setting unit includes a unit configured to set correspondence between the information on the characteristics of the recording material and the printing condition from a terminal connected to the image forming apparatus, and share the correspondence among a plurality of image forming apparatuses. The image forming apparatus according to claim 1.   The image forming apparatus according to claim 1, wherein the correspondence setting unit includes a unit capable of automatically adjusting a threshold relating to determination of the recording material according to a usage frequency of the recording material.   The image forming apparatus according to claim 1, wherein the information relating to the characteristics of the recording material includes a glossiness of the recording material.

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