JP2005031184A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus by which a recording material where a light quantity is adjusted is confirmed as a reference recording material for adjusting the light quantity and from which the recording material is removed in short time. <P>SOLUTION: The image forming apparatus provided with an exposure means, a developing means, a transfer means, a fixing means, a light irradiating means and a reading means to read and output the inside of a light irradiating area by the light irradiating means on the surface of the recording material as a video is provided with a manual paper feeding means to feed the recording material, and is provided with a light quantity controlling means to control the light quantity of the light irradiating means based on the video read by the reading means by irradiating the surface of the recording material with light from the light irradiating means. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus such as a copying machine or a laser printer.
[0002]
[Prior art]
An image forming apparatus such as a copying machine or a laser printer includes a latent image carrier that carries a latent image, and a developing unit that visualizes the latent image as a developer image by applying a developer to the latent image carrier. A transfer unit that transfers the developer image by the developing unit to a recording material conveyed in a predetermined direction; and the recording material that has received the transfer of the developer image by the transfer unit is heated under predetermined fixing processing conditions. Fixing means for fixing the developer image to the recording material by applying pressure is provided.
[0003]
FIG. 7 is a schematic cross-sectional view showing a schematic configuration of a conventional image forming apparatus 100.
[0004]
As shown in FIG. 7, the image forming apparatus 100 includes a paper cassette 111, a paper feed roller 112, a transfer belt 109, photosensitive drums 101Y, 101M, 101C, and 101Bk as latent image carriers, and transfer rollers 108Y as transfer means. 108M, 108C, 108Bk, cartridges 105Y, 105M, 105C, 105Bk, optical units 104Y, 104M, 104C, 104Bk, a fixing unit 117 as fixing means, and the like.
[0005]
In this image forming apparatus 100, yellow, magenta, cyan, and black toner images are transferred onto a recording material by using an electrophotographic process, and the recording material is transferred by a fixing roller of a fixing unit 117. The toner image is fixed on the recording material by heating and pressurizing at a predetermined temperature.
[0006]
When image data to be printed is sent from the host computer (not shown), the video controller (not shown) creates bitmap data for each side of yellow, magenta, cyan, and black according to the color image. To do.
[0007]
The optical units 104Y, 104M, 104C, and 104Bk for each color are configured to form a latent image by exposing and scanning the surface of each photosensitive drum 101Y, 101M, 101C, and 101Bk with a laser beam based on the bitmap data. In a series of image forming operations, scanning control is performed in synchronization so that the image is transferred from a predetermined position on the recording material to be conveyed. The latent images formed on the surfaces of the photosensitive drums 101Y, 101M, 101C, and 101Bk are developed by toners that are developers of the respective colors by the developing devices 106Y, 106M, 106C, and 106Bk provided in the cartridges 105Y, 105M, 105C, and 105Bk. Visualized as a toner image.
[0008]
The image forming apparatus 100 also includes a paper feed motor (not shown) that feeds and conveys a recording material, a transfer belt drive motor (not shown) that drives a transfer belt drive roller, and each color photosensitive drum 101Y, 101M. , 101C, 101Bk and transfer rollers 108Y, 108M, 108C, 108Bk, a photosensitive drum driving motor (not shown), and a fixing driving motor (not shown) for driving the fixing roller.
[0009]
The image forming apparatus 100 further includes a video reading sensor 123. The video reading sensor 123 irradiates light onto the surface of the recording material fed and conveyed from the paper cassette 111 by the paper feed roller 112, and the reflected light thereof. By focusing the light and forming an image, an image of a specific area of the recording material is detected.
[0010]
Next, the structure of the image reading sensor 123 will be described with reference to FIG.
[0011]
As shown in FIG. 2, the image reading sensor 123 includes an LED 33 as a light irradiation unit, a CMOS sensor 34 as a reading unit, lenses 35 and 36 as imaging lenses, and the like.
[0012]
Light having the LED 33 as a light source is irradiated to the surface of the recording material conveyance guide 31 or the surface of the recording material 32 on the recording material conveyance guide 31 through the lens 35.
[0013]
The reflected light from the recording material 32 is collected through the lens 36 and imaged on the CMOS sensor 34. As a result, the surface image of the recording material conveyance guide 31 or the recording material 32 is read.
[0014]
The LED 33 is arranged so that the LED light irradiates the surface of the recording material 32 obliquely at a predetermined angle as shown in FIG.
[0015]
FIG. 3 is a diagram illustrating an example of the CMOS sensor 34 of the image reading sensor 123.
[0016]
The CMOS sensor 34 is an 8 × 8 pixel sensor, and the surface image of the recording material 32 can be read by the 8 × 8 area sensor portion 38.
[0017]
FIG. 4 is a diagram showing the relationship between the surface of the recording material read by the CMOS sensor 34 of the image reading sensor 123 and an example in which the output from the CMOS sensor 34 is digitally processed to 8 × 8 pixels.
[0018]
The digital processing is performed by converting the analog output from the CMOS sensor 34 into 8-bit pixel data by A / D conversion (not shown) as conversion means.
[0019]
In FIG. 4, 40 is an enlarged image of the surface of the recording material A, which is a so-called rough paper, and the surface of the recording material B, which is a commonly used so-called plain paper. 42 is an enlarged image of the surface of the recording material C, which is glossy paper in which the paper fibers are sufficiently compressed.
[0020]
Thus, these images 40 to 42 read into the CMOS sensor 34 are digitally processed into images 43 to 45 shown in FIG.
[0021]
Thus, the image on the surface varies depending on the type of recording material. This is a phenomenon that occurs mainly because the fiber state on the paper surface is different.
[0022]
As described above, the image obtained by reading the surface of the recording material by the CMOS sensor 34 and digitally processing it can be discriminated by the surface state of the paper fiber of the recording material. Here, in order to read the surface of the recording material by the CMOS sensor 34 and determine the recording material according to the surface state of the paper fiber of the recording material, it is necessary to adjust the light amount of the LED 33 to an appropriate value. This is because if the light amount of the LED 33 is too large or too small, the dynamic range of the CMOS sensor 34 becomes narrow, and the pixel data value may be saturated when the recording material is measured. Therefore, it is necessary to always adjust the light quantity of the LED when reading the image of the recording material with the CMOS sensor 34 to an appropriate value.
[0023]
Next, a light amount adjustment method of the LED 33 related to the video reading sensor 123 provided in the image forming apparatus 100 will be described using the flowcharts of FIGS. 5 and 6.
[0024]
Conventionally, when the light amount of the LED 33 is adjusted, a standard recording material for adjusting the light amount is set on the top of the recording material set in the paper cassette 11. The standard recording material is fed from the paper cassette 11 and the recording material is stopped at the position of the video reading sensor 123. Then, the light quantity adjustment of LED33 is performed by the method demonstrated below.
[0025]
FIG. 5 is a block diagram of control means for controlling the amount of light of the LED 33 by controlling the current flowing through the LED 33.
[0026]
The CPU 51 is a CPU having an analog output port for setting a current to be passed through the LED 33, and can output an analog voltage. The analog voltage output of the CPU 51 is input to the operational amplifier 52. The operational amplifier 52 and the transistor 53 control the voltage drop of the resistor 54 due to the current flowing through the LED 33 to be equal to the analog voltage output from the CPU 51, so that the current flowing through the LED 33 can be controlled by the CPU 51.
[0027]
Next, a method for adjusting the light amount of the LED 33 provided in the image forming apparatus 100 will be described using the flowchart of FIG.
[0028]
First, the LED 33 is turned on (S62), and the CMOS sensor 34 reads the image of the recording material (S63). Then, after the LED 33 is turned off (S64), it is determined whether or not the light amount obtained from the image read by the CPU 51 is a predetermined light amount. The determination of the amount of light may be performed as follows.
[0029]
That is, the sum of all the pixels of the 8-bit digital data of each pixel of the video read data is calculated. This value increases as the amount of light increases, and decreases as the amount of light decreases. Accordingly, by comparing the total value of the digital data with a predetermined value, it can be determined whether the light amount is a predetermined light amount. When the predetermined light amount is not reached, the analog output voltage value of the CPU is adjusted so that the LED current value becomes a predetermined light amount.
[0030]
The analog output voltage value is calculated by the CPU 51. This process is made programmable by the CPU 51. For example, when the amount of reflected light reflected from the surface of the recording material is too large, the current value is reduced by an appropriate value compared to a predetermined amount of light. Or, on the contrary, if it is too small, the current value is increased by an appropriate value as compared with a predetermined light amount. By performing the above-described operation, the light amount of the LED 33 can be set to an appropriate light amount.
[0031]
A technique for adjusting the amount of light of a light source irradiated on the surface of a recording material read by a light receiving sensor such as a CCD is known (for example, see Patent Document 1).
[0032]
[Patent Document 1]
JP 2001-268322 A [Problems to be solved by the invention]
However, the above-described conventional image forming apparatus has the following problems.
[0033]
That is, since the recording material is fed from the paper cassette 111 and the light amount adjustment is performed, it cannot be visually confirmed that the recording material for which the light amount adjustment is performed is a standard recording material for light amount adjustment.
[0034]
Further, after the light amount adjustment is completed, in order to remove the recording material, it is necessary to transport the recording material on a predetermined transport path and discharge it. Alternatively, it is necessary to remove the recording material by opening the front door or pulling out the paper cassette. In any case, there is a problem that the time for removing the recording material becomes long.
[0035]
The present invention has been made in view of the above problems, and the object of the present invention is to confirm that the recording material whose light amount is adjusted is a standard recording material for adjusting the light amount, and the recording material. It is an object of the present invention to provide an image forming apparatus that can remove the toner in a short time.
[0036]
[Means for Solving the Problems]
To achieve the above object, the present invention provides an exposure means for forming a latent image on a latent image carrier by blinking light irradiation in accordance with image data, and a developer to the latent image carrier. Developing means for visualizing the latent image as a developer image, transfer means for transferring the developer image by the developing means to a recording material conveyed in a predetermined direction, and transferring the developer image by the transfer means. Fixing means for fixing the developer image to the recording material by heating and pressurizing the received recording material under predetermined fixing processing conditions; light irradiation means for irradiating light on the surface of the recording material; In the image forming apparatus including a reading unit that reads and outputs a light irradiation area of the surface of the recording material by the light irradiation unit as an image, the image forming apparatus includes a manual sheet feeding unit for feeding the recording material, and the manual sheet feeding unit And a light amount control unit that controls the light amount of the light irradiation unit based on an image read by the reading unit by irradiating the surface of the recording material with light from the light irradiation unit. Features.
[0037]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings.
[0038]
<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS.
[0039]
FIG. 1 is a schematic cross-sectional view showing a schematic configuration diagram of an image forming apparatus 100 according to the present embodiment. In FIG. 1, units that perform the same operations as those shown in FIG. Further, detailed description of what has been described in the prior art will be omitted. FIG. 2 is a diagram showing a form of the image reading sensor.
[0040]
The image forming apparatus 100 according to the present embodiment includes a manual sheet feeding unit 124. When the light amount of the LED 33 of the image reading sensor 123 is adjusted, a standard recording material for adjusting the light amount is fed from the manual sheet feeding unit 124. The recording material 32 set in the manual paper feeding unit 124 is fed to the position of the registration roller 115 by the paper feeding roller 125. Here, the image reading sensor 123 can irradiate a standard recording material.
[0041]
Then, the light quantity adjustment of LED33 is performed by the method demonstrated previously. After the light amount adjustment of the LED 33 is completed, the image of the recording material is read with the adjusted LED light amount. The paper type of the recording material can be determined using the data read by the video reading sensor 123.
[0042]
Next, a paper type discrimination method for the recording material will be described.
[0043]
When performing the printing operation, the recording material is fed to the position of the registration roller 115 and the image on the surface of the recording material is read by the image reading sensor 123.
[0044]
In this case, paper feeding may be performed from the paper cassette 11 or from the manual paper feeding unit 124. The paper type of the recording material is determined by comparing the read video. In the image comparison calculation, the maximum density pixel Dmax and the minimum density pixel Dmin are derived from the result of reading the images of a plurality of locations on the surface of the recording material. This is averaged in parallel for each read video.
[0045]
That is, when the paper fiber on the surface is rough like the recording material A in FIG. 4, many shadows of the fiber are generated. As a result, the difference between the bright part and the dark part is large, and Dmax−Dmin becomes large.
[0046]
On the other hand, on the surface such as the recording material C, the shadow of the fiber is small and Dmax−Dmin is small.
[0047]
This comparison determines the paper type of the recording material. The determination result of the paper type of the recording material can be used to set the temperature of the fixing unit 117. For example, the fixing temperature is increased if the surface paper fiber is rough like the recording material A shown in FIG. 4, and the fixing temperature is decreased if the surface paper fiber is smooth like the recording material C. The temperature control of the fixing unit 117 can be performed by setting.
[0048]
As described above, according to the present embodiment, the recording material is visually observed from the manual paper feeding unit by feeding the standard recording material for light quantity adjustment from the manual paper feeding unit and adjusting the light amount of the LED 33. Therefore, it can be confirmed that the recording material whose light amount is adjusted is a standard recording material for light amount adjustment. Further, since the recording material remaining on the manual sheet feeding means is only removed after the light amount adjustment is completed, the time for removing the recording material can be shortened.
[0049]
<Embodiment 2>
Next, a second embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected about the structure similar to Embodiment 1, and the description is abbreviate | omitted.
[0050]
FIG. 8 is a block diagram for explaining the present embodiment. The present embodiment is different from the first embodiment in that the image forming apparatus 100 includes a nonvolatile memory 55.
[0051]
FIG. 9 is a flowchart for illustrating a method of controlling the light amount adjustment of the LED 33 according to the present embodiment.
[0052]
First, the LED 33 is turned on (S92), and the CMOS sensor 34 reads the image of the recording material (S93). Then, after the LED 33 is turned off (S94), it is determined by the above-described method or the like whether or not the predetermined light quantity is predetermined. If the predetermined light amount is not reached, the CPU 51 calculates the current value so that the LED current value becomes a predetermined light amount. This process is processed by the CPU 51 in a programmable manner. For example, when the amount of reflected light reflected from the surface of the recording material is too large, the current value is reduced by an appropriate value compared to a predetermined amount of light. Or, on the contrary, if it is too small, the current value is increased by an appropriate value as compared with the predetermined light amount. In order to control the light amount of the LED 33 obtained in this way to an appropriate light amount, the current value to be passed through the LED 33 is stored in the nonvolatile memory 55 (S97).
[0053]
As described above, by storing the current value in the nonvolatile memory 55, an appropriate current value can be stored even after the main power supply of the image forming apparatus 100 is turned off. Therefore, the light amount adjustment of the LED 33 may be performed only once at the time of factory shipment, and there is an advantage that the user does not need to adjust the light amount.
[0054]
<Embodiment 3>
Next, a third embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected about the structure similar to Embodiment 1, and the description is abbreviate | omitted.
[0055]
FIG. 10 is a flowchart for illustrating a control method of light amount adjustment of the LED 33 in the present embodiment.
[0056]
First, the LED 33 is turned on (S102), and the CMOS sensor 34 reads the image of the recording material (S103). Thereafter, the registration roller 115 is rotated to convey and stop the recording material 32 (S105). The CMOS sensor 34 reads the image of the recording material 32. This operation is repeated n times.
[0057]
By performing the reading operation described above, a large number of the video data can be obtained. All of this video data is A / D converted to obtain the total. The total value is compared with a predetermined value, and it is determined whether the light quantity of the LED 33 is appropriate. The subsequent light amount adjustment method is the same as the method described in the first embodiment.
[0058]
As described above, by reading the video at a plurality of locations on the recording material a plurality of times, it is possible to reduce the influence of variations due to the measurement location of the recording material. Therefore, more reliable LED light amount adjustment can be performed. The reliability increases as the number of readings n increases. However, increasing the number of readings n increases the time required for LED light amount adjustment, and therefore the number of readings may be set individually in the image forming apparatus.
[0059]
【The invention's effect】
As apparent from the above description, according to the present invention, the recording material can be visually observed from the manual paper feeding means by feeding a standard recording material from the manual paper feeding means and adjusting the light quantity of the LED. Therefore, it can be confirmed that the recording material on which the light amount is adjusted is a standard recording material for adjusting the light amount.
[0060]
Further, since the recording material remaining on the manual sheet feeding means is only removed after the light amount adjustment is completed, the time for removing the recording material can be shortened.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing a schematic configuration of an image forming apparatus according to the present invention.
FIG. 2 is a diagram illustrating a schematic configuration of a reading unit provided in the image forming apparatus according to the present invention.
FIG. 3 is a diagram illustrating a configuration of a reading unit provided in the image forming apparatus according to the present invention.
FIG. 4 is a diagram illustrating a relationship between the surface of a recording material read by a reading unit and an example in which an output from the reading unit is digitally processed.
FIG. 5 is a block diagram for explaining LED light amount adjusting means in the present invention.
FIG. 6 is a flowchart for explaining LED light amount adjustment control in the present invention.
FIG. 7 is a schematic cross-sectional view showing a schematic configuration of a conventional image forming apparatus.
FIG. 8 is a block diagram for explaining LED light amount adjusting means in Embodiment 2 of the present invention.
FIG. 9 is a flowchart for explaining LED light amount adjustment control according to Embodiment 2 of the present invention;
FIG. 10 is a flowchart for explaining LED light amount adjustment control according to Embodiment 3 of the present invention;
[Explanation of symbols]
32 Recording material (recording material)
33 LED (light irradiation means)
34 CMOS sensor (reading means)
35, 36 lens (imaging lens)
100 Image forming apparatus 101 Photosensitive drum (latent image carrier)
102 Charging roller 104 Optical unit 105 Cartridge 106 Developing means 108 Transfer roller (transfer means)
111 Paper cassette 112 Paper feed roller 115 Registration roller 117 Fixing unit (fixing means)
123 Image reading sensor 124 Manual paper feed means 125 Paper feed roller

Claims (5)

Exposure means for forming a latent image on the latent image carrier by flashing light irradiation according to image data, and visualizing the latent image as a developer image by applying a developer to the latent image carrier. A developing unit; a transfer unit that transfers the developer image by the developing unit to a recording material conveyed in a predetermined direction; and the recording material that has received the transfer of the developer image by the transfer unit. Fixing means for fixing the developer image to the recording material by heating and pressurizing at, a light irradiation means for irradiating light on the surface of the recording material, and light by the light irradiation means on the surface of the recording material In an image forming apparatus including a reading unit that reads and outputs an image in an irradiation area,
A manual paper feed unit for feeding the recording material, the recording material is fed from the manual paper feed unit, and the surface of the recording material is irradiated with light from the light irradiation unit and read by the reading unit; An image forming apparatus comprising: a light amount control unit that controls a light amount of the light irradiation unit based on the image. The image forming apparatus according to claim 1, further comprising a plurality of paper feeding units. The image forming apparatus according to claim 1, wherein the light irradiation unit is an LED. The light amount control unit includes a calculation unit for calculating a current value to be supplied to the LED based on an image read by the reading unit, and supplies an optimum current value to be supplied to the LED. The image forming apparatus according to claim 3. 5. The image forming apparatus according to claim 4, further comprising a storage unit for storing a current value of the light irradiation unit for irradiating the light irradiation unit after the light amount adjustment.

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