Image formation device, image formation device control method and image formation device control program

Abstract

To suppress a used amount of a non-volatile memory for writing a residual life by suppressing a data amount that indicates the residual life of a laser diode in an image formation device.SOLUTION: An image formation device has: a writing unit having a light source, a light source control part which controls the light source according to a lighting signal, and a non-volatile memory; an image data generation part for generating image data; a lightening information generation part which generates the lightening signal and lightening time information corresponding to the lightening signal according to the image data generated by the image data generation part; a current value integration part which integrates a driving current used for formation of an image corresponding to the image data as a total driving current value by using the lightening time information and driving current information indicating the driving current of the light source; and an integration value conversion part which on the basis of a life determination instruction, converts the total driving current value into an index of the residual life of the light source by using a life current value which is a specification value of the total driving current until the light source reaches an end of life thereof, and writes the converted index to the non-volatile memory.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an image forming apparatus, a control method for the image forming apparatus, and a control program for the image forming apparatus.

Background Art

[0002] An electrophotographic image forming apparatus that forms an image by irradiating a photosensitive drum with laser light from a laser diode is known. In this type of image forming apparatus, the emission time of the laser diode is integrated and stored in a non-volatile memory, and the remaining life of the laser diode is calculated using the integrated value of the stored emission time and the design life value (see, for example, Patent Document 1).

Summary of the Invention

Problems to be Solved by the Invention

[0003] However, for example, when the storage capacity of the non-volatile memory for storing the integrated value of the emission time is small and information other than the integrated value is also stored in the non-volatile memory, there is a risk that the storage capacity will be insufficient. For this reason, it is preferable that the amount of data indicating the remaining life of the laser diode is small.

[0004] In view of the above problems, an object of the present invention is to suppress the amount of data indicating the remaining life of a laser diode in an electrophotographic image forming apparatus equipped with the laser diode, thereby suppressing the amount of use of a non-volatile memory for writing the remaining life.

Means for Solving the Problems

[0005] In order to solve the above technical problem, an image forming apparatus according to an aspect of the present invention includes a writing unit having a light source, a light source control unit that controls the light source according to a lighting signal, and a nonvolatile memory, an image data generation unit that generates image data, a lighting information generation unit that generates the lighting signal and lighting time information corresponding to the lighting signal according to the image data generated by the image data generation unit, a current value integration unit that integrates, as a total drive current value, the drive current used for forming an image corresponding to the image data using the lighting time information and drive current information indicating the drive current of the light source, and an integrated value conversion unit that, based on a life determination instruction, converts the total drive current value into an index of the life of the light source using a life current value that is a specification value of the total drive current until the light source reaches the end of its life, and writes the converted index into the nonvolatile memory.

Advantages of the Invention

[0006] In an electrophotographic image forming apparatus equipped with a laser diode, by suppressing the amount of data indicating the remaining life of the laser diode, the usage amount of the nonvolatile memory for writing the remaining life can be suppressed.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0008] Hereinafter, embodiments will be described with reference to the drawings. In each drawing, the same reference numerals are given to the same components, and redundant descriptions may be omitted.

[0009] (Overall Configuration of Image Forming Apparatus) FIG. 1 is a perspective sectional view showing an example of the overall configuration of an image forming apparatus according to an embodiment of the present invention. The image forming apparatus 100 shown in FIG. 1 is, for example, an electrophotographic multifunction peripheral (MFP: Multifunction Peripheral / Printer / Product) including a copy function, a FAX function, a print function, a scanner function, and the like.

[0010] The image forming apparatus 100 can mutually switch operation modes for realizing a copy function, a print function, a scanner function, a facsimile function, and the like. Further, the image forming apparatus 100 may be switched to a normal mode, a power saving mode, or the like according to the state of the internal circuit.

[0011] The image forming apparatus 100 includes an ADF (Automatic Document Feeder) 10, an image reading unit 20, an image forming unit 30, a paper feeding unit 40, and an operation unit 50. The ADF 10 feeds the originals one by one to the image reading unit 20. The image reading unit 20 generates image data by optically reading the image information of each original sequentially sent from the ADF 10. The image reading unit 20 is an example of an image data generation unit. The operation unit 50 has an operation panel (not shown) that, for example, accepts various inputs according to the operations of the user and displays various information.

[0012] The image forming unit 30 includes a writing device 110, a photosensitive drum 150, a developing device 160, an intermediate transfer belt 170, a secondary transfer belt 180, and a fixing device 190. For the sake of easy understanding of the explanation, in FIG. 1, the image forming unit 30 is shown in a state where its interior is seen through. The writing device 110 includes an image writing control unit 120 and a writing unit 130 including a laser diode LD (Laser Diode). The image writing control unit 120 and the writing unit 130 will be described with reference to FIG. 2. The intermediate transfer belt 170 and the secondary transfer belt 180 are examples of transfer devices. The laser diode LD is an example of a light source.

[0013] For example, the image forming apparatus 100 employs a so-called tandem method, and the photosensitive drum 150 and the developing device 160 are provided for each of the colors yellow (Y), magenta (M), cyan (C), and black (K). The paper feeding unit 40 includes a plurality of recording paper cassettes 41 and a paper feeding device 42 that conveys the recording paper stored in the recording paper cassettes 41 to the image forming unit 30.

[0014] The image forming unit 30 generates image data by reading a document with an image reading unit provided in the ADF 10. The image forming unit 30 exposes each photosensitive drum 150 with the writing device 110 based on the generated image data, and forms an electrostatic latent image for each color on each photosensitive drum 150. The image forming unit 30 develops the electrostatic latent image by supplying toners of different colors to each photosensitive drum 150 on which the electrostatic latent image is formed with the developing device 160, and forms a toner image for each color on each photosensitive drum 150.

[0015] The image forming unit 30 transfers the toner image from the photosensitive drum 150 to the intermediate transfer belt 170, and transfers the toner image on the intermediate transfer belt 170 to a recording paper conveyed from the paper feeding unit 40 to the secondary transfer belt 180. Then, the image forming unit 30 melts the toner of the toner image transferred to the recording paper with the fixing device 190 and fixes the color image on the recording paper, thereby completing the image forming process. Hereinafter, the operation from the reading of the document by the image forming unit 30 to the fixing of the toner image on the recording paper is also referred to as a printing operation. Note that a recording medium such as a plastic sheet on which the toner image can be melted and fixed may be used instead of the recording paper.

[0016] The lifespan of the laser diode LD included in the writing device 110 is usually longer than the usage period of the image forming apparatus 100. Hereinafter, the usage period of the image forming apparatus 100 is also referred to as the lifespan of the image forming apparatus 100. The laser diode LD is incorporated and integrated into the writing unit 130. Therefore, the lifespan of the laser diode LD is also the lifespan of the writing unit 130.

[0017] In this case, the writing unit 130 is taken out from the used image forming apparatus 100, and the taken-out writing unit 130 is attached to another image forming apparatus 100 for reuse. At this time, lifespan management is required to prevent the laser diode LD included in the writing unit 130 to be reused from reaching its lifespan during the use of the image forming apparatus 100 to which it is reused.

[0018] (Example of a writing device) FIG. 2 is a block diagram showing an example of the writing device 110 in FIG. 1. The image writing control unit 120 of the writing device 110 includes a lighting information generation unit 121 and a life conversion unit 122. The life conversion unit 122 includes a current value integration unit 123, an integrated value storage unit 124, and an integrated value conversion unit 125. For example, the life conversion unit 122 may be realized by a control program executed by a processor such as a CPU (Central Processing Unit) mounted on the writing device 110.

[0019] The writing unit 130 includes an LD control unit 131 including a non-volatile memory 132 and four laser units 133 each including a laser diode LD. For example, the writing unit 130 has a substrate form. The LD control unit 131 functions as an LD driver and controls the operation of the laser diode LD. The LD control unit 131 is an example of a light source control unit. The laser diodes LD mounted on the four laser units 133 can each emit laser light used for forming images of black K, yellow Y, cyan C, and magenta M.

[0020] Based on the image data and image information output from the image reading unit 20, the lighting information generation unit 121 generates a lighting signal for each color of each pixel that controls the lighting of each laser diode LD, and lighting data corresponding to the lighting signal. For example, the lighting data includes the number of pixels of the image data and density information for each pixel, and is an example of lighting time information corresponding to the lighting signal. The density information may include luminance information for each color (Y, M, C, K). Note that the lighting data may be data for each color or data obtained by adding the four colors together. The lighting information generation unit 121 outputs the generated four lighting signals (Y, M, C, K) to the LD control unit 131 and outputs the lighting data to the current value integration unit 123.

[0021] The current value integration unit 123 receives the lighting data for each pixel from the lighting information generation unit 121 and receives the drive current information indicating the actual drive current of the laser diode LD from the LD control unit 131. Based on the lighting data and the drive current information, the current value integration unit 123 integrates the drive current values of the laser diode LD and calculates the integrated drive current value of the laser diode LD corresponding to the image data for one page.

[0022] The drive current information output by the LD control unit 131 may be information for each laser diode LD (for each color) or information for the four combined laser diodes LD. Each time the current value integration unit 123 calculates the integrated drive current value for one page, it writes the calculated integrated drive current value into the integrated value storage unit 124. At this time, the current value integration unit 123 adds the new integrated drive current value to the integrated drive current value stored in the integrated value storage unit 124 to integrate the total drive current value A. Hereinafter, "drive current" such as drive current, drive current value, total drive current value, etc. is assumed to be the drive current of the laser diode LD even if not specifically specified.

[0023] When the drive current information for each laser diode LD is output from the LD control unit 131, the current value integration unit 123 may calculate the integrated drive current value for each laser diode LD and add the largest integrated drive current value to the integrated drive current value stored in the integrated value storage unit 124. Also, if the laser diode LD with a high usage frequency is known in advance, the integrated drive current value of the laser diode LD with the highest usage frequency may be calculated. Thereby, the life degree value Y1 generated by the integrated value conversion unit 125 can be calculated to be larger, and it is possible to prevent the laser diode LD from failing due to its life before the image forming apparatus 100 reaches the end of its life.

[0024] For example, the integrated value storage unit 124 is a non-volatile memory such as a flash memory, and can hold the total drive current value A without loss even when the power of the image forming apparatus 100 is cut off. When the writing unit 130 is new, before the image forming apparatus 100 is shipped, the total drive current value A indicating zero is written into the integrated value storage unit 124. When the writing unit 130 is a reused item, before the image forming apparatus 100 is shipped, the total drive current value A calculated before reuse is held in the integrated value storage unit 124.

[0025] When the integrated value conversion unit 125 receives from outside the writing apparatus 110 a life determination instruction which is an instruction to determine the life of the writing unit 130, it reads out the total drive current value A stored in the integrated value storage unit 124, and converts the read total drive current value A into a life degree value Y1 indicating the degree of remaining life of the writing unit 130. The integrated value conversion unit 125 writes the converted life degree value Y1 into the non-volatile memory 132 of the LD control unit 131. The life degree value Y1 is an example of an index of the remaining life of the laser diode LD.

[0026] For example, the non-volatile memory 132 is a small-capacity memory mounted on the LD control unit 131, and holds, in addition to the life degree value Y1, a plurality of parameters etc. used in the writing unit 130. Although not particularly limited, the storage capacity of the non-volatile memory 132 is about 64 bits to 256 bits.

[0027] The smaller the data amount of the life degree value Y1, the more the storage area allocated to the parameters etc. in the non-volatile memory 132 can be increased, and the possibility that the life degree value Y1 and the parameters etc. cannot be stored in the non-volatile memory 132 can be reduced. Then, the life degree value Y1 for determining the reusability of the writing unit 130 can be held with a small memory usage amount and passed on to a plurality of image forming apparatuses 100. A method for determining the reusability of the writing unit 130 will be described with reference to FIG. 8.

[0028] For example, when the total size of the life degree value Y1 and parameters exceeds the storage capacity of the non-volatile memory 132, it is necessary to use another LD control unit equipped with a non-volatile memory having a larger storage capacity. However, when another LD control unit with a large storage capacity of the non-volatile memory has not been commercialized, it is necessary to mount a single non-volatile memory in the writing unit 130, and the cost of the writing unit 130 increases significantly.

[0029] When the image forming unit 30 performs a printing operation, the LD control unit 131 outputs a driving current for each pixel to the four laser diodes LD in response to a lighting signal. The LD control unit 131 receives light amount information (current value information) for each pixel corresponding to the driving current from the four laser diodes LD. The LD control unit 131 outputs the light amount information as driving current information to the current value integration unit 123 of the life conversion unit 122.

[0030] For example, the print information of an image printed on a recording sheet can be calculated by Equation (1). In Equation (1), the maximum required light amount is the power per pixel calculated using the measurement of the current value of the laser diode LD, temperature, light amount, etc., and is assumed to be 15 mW, for example, below. Print information = number of pixels per sheet × maximum required light amount × number of printed sheets... (1)

[0031] For example, assume that the writing unit 130 (i.e., the laser diode LD) fails due to its lifespan when printing 200,000 sheets in one year, double-sided on A3 paper, with solid single-sided writing at 1200 dpi. In this case, using Equation (1), the value of the print information is 8.35×10 14 which, when represented in binary, requires 50 bits. Therefore, when writing the print information calculated by Equation (1) directly to the non-volatile memory 132, a storage area of 50 bits is required. For example, when the storage capacity of the non-volatile memory is 64 bits, only 14 bits of storage capacity remain after writing the print information.

[0032] Therefore, in this embodiment, instead of calculating the print information represented by an absolute value as shown in Equation (1), a remaining life degree value Y1 represented by a relative value is calculated and written into the non-volatile memory 132, thereby reducing the usage amount of the non-volatile memory 132. The remaining life degree value Y1 is calculated by Equation (2), and the smaller the value, the more margin there is until the end of the life (the remaining life is long), and when the value is "1", it indicates that the life has been reached.

Number

[0033] In Equation (2), the symbol A [A·sec] represents the total drive current value A obtained by adding the drive current integrated value held in the integrated value storage unit 124 of FIG. 2. The symbol A(max) [A·sec] represents the life current value, which is the total drive current value until the laser diode LD fails due to the life. For example, the life current value of the laser diode LD is defined by the rated current × the guaranteed lighting time.

[0034] The symbol n represents a correction coefficient determined by a prior measurement of the laser diode LD. The correction coefficient n is set to a value of "1" or more. The larger the correction coefficient n, the earlier the remaining life degree value Y1 reaches "1". Therefore, for example, even when the remaining life degree value Y1 is calculated to be smaller than the actual remaining life degree due to variations in the characteristics of the laser diode LD, etc., the arrival of the life can be appropriately determined.

[0035] The symbol A in Equation (2) represents the total drive current value A added to the integrated value storage unit 124 and can be calculated by Equation (3). In Equation (3), the drive current represents the drive current per pixel. A = drive current [A] × lighting time per pixel [sec] × total number of pixels ··· (3)

[0036] For example, when determining the lifetime of the laser diode LD when the lifetime value Y1 of Equation (2) is "1.000" or more, "0.000" to "1.000" can be represented by 10 bits. That is, the storage capacity of the non-volatile memory 132 for holding the lifetime value Y1 only needs to be 10 bits. For example, when the maximum number of printed sheets until the laser diode LD reaches the end of its life is 200,000 sheets, the lifetime value Y1 increases by 1 count (0.001) every time 200 sheets are printed.

[0037] For example, the determination of whether the writing unit 130 taken out from the image forming apparatus 100 can be attached to another image forming apparatus 100, that is, the determination of whether there is sufficient remaining life in the writing unit 130, is performed using Equation (4). 1 - Y1 > Y(max) ··· (4)

[0038] In Equation (4), 1 - Y1 indicates the degree of remaining life of the laser diode LD. The closer it gets to the end of the life of the laser diode LD, the smaller the value becomes, and "0" indicates that the end of the life has been reached. Y(max) indicates the degree of device usage, which is the degree of the total drive current until the end of the life of the image forming apparatus 100 with respect to the life current value A(max), which is the total drive current value until the end of the life of the laser diode LD, and is represented by Equation (5).

Equation

[0039] In Equation (5), the drive current indicates the drive current of the laser diode LD per pixel. The average number of pixels indicates the average number of pixels (predicted value) of the image printed on the recording paper until the end of the life of the image forming apparatus 100, and the number of printed sheets indicates the number of printed sheets (predicted value) until the end of the life of the image forming apparatus 100. That is, the device usage degree Y(max) indicates what ratio the drive current until the end of the life of the image forming apparatus 100 is with respect to the life current value A(max), which is the total drive current until the end of the life of the laser diode LD.

[0040] Therefore, in Equation (4), when the remaining life ratio (1 - Y1) is greater than the device usage ratio Y(max), it indicates that the writing unit 130 is less likely to fail due to its lifespan before the image forming apparatus 100 reaches the end of its lifespan. That is, it indicates that the writing unit 130 is reusable. On the other hand, when the remaining life ratio (1 - Y1) is less than or equal to the device usage ratio Y(max), it indicates that the writing unit 130 is highly likely to fail due to its lifespan during the use of the image forming apparatus 100. That is, it indicates that the writing unit 130 is not reusable.

[0041] By the way, since the lifespan of the writing unit 130 is several times that of the image forming apparatus 100, the writing unit 130 can be used successively in multiple image forming apparatuses 100. For this reason, the lifespan ratio value Y1 written in the non-volatile memory 132 also needs to be passed on among multiple image forming apparatuses 100. Hereinafter, it is assumed that the correction coefficient n in Equation (2) is "1".

[0042] Equation (6) shows a method for calculating a new lifespan ratio value Y2 when the writing unit 130 mounted in the first image forming apparatus 100 that has reached the end of its lifespan is reused in the second image forming apparatus 100. For example, when receiving a lifespan determination instruction, the integrated value conversion unit 125 reads the lifespan ratio value Y1 from the non-volatile memory 132, and if the read lifespan ratio value Y1 is not "0", calculates a new lifespan ratio value Y2 using the lifespan ratio value Y1. Then, the integrated value conversion unit 125 overwrites the calculated lifespan ratio value Y2 in the non-volatile memory 132.

Equation

[0043] In Equation (6), Y1 × A(max) represents the total drive current value A calculated from the lifespan ratio value Y1 in the first image forming apparatus 100 before reuse, which is held in the non-volatile memory 132 of the LD control unit 131 of the second image forming apparatus 100 during reuse.

[0044] The symbol A2 indicates the total drive current value obtained by adding the drive current integrated value held in the integrated value storage unit 124 of FIG. 2, similar to the symbol A in Equation (2). The symbol n2 indicates a correction coefficient determined by measurement during reuse of the laser diode LD, and is set to a value of "1" or more, similar to the symbol n in Equation (2). Then, the remaining life value Y2 carried over from the remaining life value Y1 is the value obtained by adding the remaining life value "(A2 × n2) / A(max)" in the second image forming apparatus 100 to the remaining life value Y1. The remaining life value "(A2 × n2) / A(max)" can be calculated in the same manner as Equation (2).

[0045] Equation (7) shows a method for calculating the remaining life value Y a when the writing unit 130 is sequentially used in three or more image forming apparatuses 100.

Equation

[0046] Equation (7) is the same as Equation (6), except that Y1, A2, and n2 in Equation (6) are replaced with Y a-1 , A a , n a respectively. The symbol A a indicates the total drive current value obtained by adding the drive current integrated value held in the integrated value storage unit 124 of the writing device 110 mounted in the a-th image forming apparatus 100, similar to the symbol A in Equation (2). The symbol n a indicates a correction coefficient determined by measurement during the a-th reuse of the laser diode LD, and is set to a value of "1" or more, similar to the symbol n in Equation (2). The remaining life value Y a-1 is the remaining life value written to the non-volatile memory 132 when the (a - 1)-th image forming apparatus 100 reaches the end of its life, and is held in the non-volatile memory 132 in the writing unit 130 reused in the a-th image forming apparatus 100.

[0047] From the above, even when the writing unit 130 is reused multiple times, the remaining life values Y1, Y2, Y a-1 , Ya They can be sequentially inherited. As a result, when the image forming apparatus 100 reaches the end of its life, it is possible to appropriately determine whether the writing unit 130 can be reused by using the minimum storage area of the non-volatile memory 132.

[0048] (Outline of the mechanism of the writing unit) Figs. 3 to 5 are explanatory diagrams showing an outline of the mechanism of the writing unit 130 in Fig. 2. In Figs. 3 to 5, the members labeled with the symbols K, Y, C, and M respectively correspond to the four color photoreceptor drums 150. The "-1" at the end of the symbol indicates the member corresponding to cyan C and magenta M, and the "-2" at the end of the symbol indicates the member corresponding to black K and yellow Y. The writing unit 130 forms laser light used for forming images of black K, yellow Y, cyan C, and magenta M on the corresponding photoreceptor drums 150 respectively.

[0049] The writing unit 130 includes a laser unit 133 including a laser diode LD, a cylindrical lens 141, mirrors 142 (142-1, 142-2), and a polygon mirror 134 which is a rotating polygon mirror. The writing unit 130 also includes fθ lenses 135 (135-1, 135-2), mirrors 136, 137, 138, 143, synchronous detection lenses 144 (144-1, 144-2), and synchronous detection sensors 145 (145-1, 145-2). Note that since the laser unit 133, the cylindrical lens 141, and the mirror 142 are located on the main scanning direction side of the polygon mirror 134 and the fθ lens 135, they are not shown in Fig. 3. The main scanning direction is the axial length direction of the photoreceptor drum 150.

[0050] In FIG. 4, the laser light emitted from the laser diode LD mounted on each color laser unit 133 is incident on the cylindrical lens 141. The cylindrical lens 141 has a refractive index determined in the sub-scanning direction, condenses the beam emitted from the laser unit 133 in the sub-scanning direction, and makes it incident on the mirror surface of the polygon mirror 134. The polygon mirror 134 rotates at high speed by a built-in motor, deflects the incident laser light in the main scanning direction, passes through the fθ lens 135, and guides it to the mirror 136. Note that the sub-scanning direction is the conveyance direction of the recording paper.

[0051] In the writing unit 130, one polygon mirror 134 is disposed at the center, and the laser units 133, mirrors 136, 137, 138, 142, 143, cylindrical lens 141, fθ lens 135, synchronous detection lens 144, and synchronous detection sensor 145 are disposed substantially symmetrically about the polygon mirror 134. Then, as shown in FIGS. 3 to 5, the optical paths of the laser lights of black K and yellow Y are laid out on the left side of the polygon mirror 134, and the optical paths of the laser lights of cyan C and magenta M are laid out on the right side of the polygon mirror 134. Thereby, the laser light deflected in the main scanning direction by one polygon mirror 134 can be sequentially reflected by the mirrors 136, 137, 138 and guided to the photosensitive drums 150 corresponding to black K, yellow Y, cyan C, and magenta M, respectively.

[0052] In FIG. 5, the laser light reflected by the mirror 137 at a specific position in the main scanning direction is reflected by the mirror 143 toward the synchronous detection lens 144. The synchronous detection lens 144 condenses the incident laser light on the synchronous detection sensor 145. Then, the synchronous detection sensor 145-1 detects the timing of the laser lights of cyan C and magenta M. The synchronous detection sensor 145-2 detects the timing of the laser lights of black K and yellow Y.

[0053] (Examples of drive current and light quantity of laser diode) FIG. 6 is an explanatory diagram showing an example of the drive current and the amount of light of the laser diode LD in FIG. 2. The laser diode LD is known to have a varying lifespan depending on temperature and drive current. The drive current of the laser diode LD increases as the amount of light increases. Also, when the laser diode LD outputs a constant amount of light, the drive current increases as the temperature rises. The higher the temperature of the laser diode LD, the greater the drive current required to emit the same amount of light, which increases the burden on the laser diode LD and shortens its lifespan.

[0054] (Example of processing when reusing the writing unit) FIG. 7 is a flowchart showing an example of the processing performed when removing the writing unit 130 in FIG. 5 from the image forming apparatus for reuse. The processing shown in FIG. 7 is carried out by an integrated value conversion unit 125 realized by a processor such as a CPU mounted on the writing device 110 executing a control program. That is, FIG. 7 shows an example of the processing by the control method and the control program of the image forming apparatus 100.

[0055] In step S10, the integrated value conversion unit 125 waits, for example, via the operation unit 50 of the image forming apparatus 100 until it receives an instruction for determining the lifespan of the writing unit 130. When the integrated value conversion unit 125 receives the lifespan determination instruction, it performs step S12. Note that the lifespan determination instruction may be issued via a communication interface mounted on the image forming apparatus 100.

[0056] Next, in step S12, the integrated value conversion unit 125 converts the total drive current value A stored in the integrated value storage unit 124 into a lifespan degree value Y1 indicating the degree of the product lifespan of the laser unit 133 using Equation (2).

[0057] Next, in step S14, the integrated value conversion unit 125 writes the degree-of-life value Y1 converted in step S12 into the non-volatile memory 132 of the writing unit 130 as the remaining life data of the laser unit 133, and ends the process shown in FIG. 7. Note that since the laser unit 133 is integrated with the writing unit 130, the remaining life of the laser unit 133 also indicates the remaining life of the writing unit 130.

[0058] After the degree-of-life value Y1 is written into the non-volatile memory 132, the writing unit 130 is removed from the image forming apparatus 100. Thereafter, it is determined by the process shown in FIG. 8 whether the removed laser unit 133 can be reused.

[0059] (Example of determination process for reusability of writing unit) FIG. 8 is a flowchart showing an example of a process for determining whether the writing unit 130 taken out from the image forming apparatus 100 can be reused. The process shown in FIG. 8 is executed by a determination program executed by a determination device installed at the manufacturing site or the reuse processing site of the image forming apparatus 100. For example, the process shown in FIG. 8 starts when the writing unit 130 is electrically connected to the determination device.

[0060] First, in step S21, the determination device reads the degree-of-life value Y1 of the writing unit 130 from the non-volatile memory 132 of the writing unit 130.

[0061] Next, in step S22, the determination device performs the determination of Expression (4) to determine whether the writing unit 130 fails due to its life before the image forming apparatus 100 using the writing unit 130 reaches the end of its life. That is, it is determined whether the life of the writing unit 130 is longer than the life of the image forming apparatus 100. When the determination device determines that the writing unit 130 does not fail before the image forming apparatus 100 reaches the end of its life, the determination device performs step S23. When the determination device determines that the writing unit 130 fails before the image forming apparatus 100 reaches the end of its life, the determination device performs step S24.

[0062] In step S23, the determination device determines to reuse the writing unit 130 and ends the process shown in FIG. 8. The writing unit 130 for which reuse has been determined is mounted on, for example, a new image forming apparatus 100.

[0063] When the writing unit 130 is mounted on a new image forming apparatus 100 and reused, as shown in Expressions (6) and (7), the lifetime degree value Y1 or the lifetime degree value Y stored in the nonvolatile memory 132 a-1 is read out and used, whereby the lifetime degree value Y of the writing unit 130 a (where a is an integer of 1 or more) can be carried over.

[0064] In step S24, the determination device determines not to reuse the writing unit 130 and ends the process shown in FIG. 8. The writing unit 130 for which non-reuse has been determined is discarded, for example.

[0065] <Hardware Configuration of Control Board> FIG. 9 is a block diagram showing an example of the hardware configuration of the image writing control unit 120 in FIG. 5. For example, FIG. 9 shows the control board 200 of the image writing control unit 120.

[0066] The control board 200 is equipped with a CPU 210, a ROM (Read Only Memory) 220, a RAM (Random Access Memory) 230, and a flash memory 240. The control board 200 is also equipped with an input interface unit 250, an output interface unit 260, an input / output interface unit 270, and a communication interface unit 280. For example, the CPU 210, the ROM 220, the RAM 230, the flash memory 240, the input interface unit 250, the output interface unit 260, the input / output interface unit 270, and the communication interface unit 280 are interconnected via a bus BUS.

[0067] The CPU 210 executes various programs such as an OS, an application, and a control program for executing the processes shown in FIG. 7. The ROM 220 holds a basic program and various parameters for making the various programs executable by the CPU 210. The RAM 230 stores the various programs executed by the CPU 210 and the data used in the programs. For example, the flash memory 240 functions as the integrated value storage unit 124 in FIG. 5 and is used for adding the integrated drive current value of the drive current to the total drive current value A.

[0068] The input interface unit 250 is connected to the image reading unit 20 and receives image data and image information from the image reading unit 20. Further, the input interface unit 250 is connected to the operation unit 50 and receives a life determination instruction for the writing unit 130 from the operation unit 50. Note that the life determination instruction may be received from a network or the like via the communication interface unit 280. Furthermore, the input interface unit 250 is connected to the LD control unit 131 and receives drive current information from the LD control unit 131.

[0069] The output interface unit 260 is connected to the LD control unit 131 of the writing unit 130 and outputs a lighting signal to the LD control unit 131. The input / output interface unit 270 is connected to the nonvolatile memory 132, writes the life degree value Y1 to the nonvolatile memory 132, and reads the life degree value Y1 from the nonvolatile memory 132. The communication interface unit 280 is connected to a network.

[0070] When various programs such as a control program for controlling the operation of the image forming apparatus 100 are stored in a recording medium, the programs may be transferred from the recording medium to the RAM 230 or the like via the input interface unit 250 or the communication interface unit 280.

[0071] As described above, in this embodiment, instead of the print information indicated by an absolute value obtained by multiplying the number of pixels, the maximum required light amount, the number of printed sheets, etc., a lifetime degree value Y1, which is a relative value, is calculated and written into the non-volatile memory 132. Thereby, the usage amount of the non-volatile memory 132 can be minimized, and the storage area assigned to parameters other than the lifetime degree value Y1 in the non-volatile memory 132 can be increased. As a result, the lifetime degree value Y1 for determining whether the writing unit 130 can be reused can be held with a small memory usage amount and can be passed on to a plurality of image forming apparatuses 100.

[0072] By reading out the lifetime degree value Y1 held in the non-volatile memory 132 and comparing it with the apparatus usage degree Y(max), which is the degree of the total drive current until the end of the life of the image forming apparatus 100, it is possible to determine whether the writing unit 130 can be reused.

[0073] By using the drive current information indicating the actual drive current of the laser diode LD, the integrated value of the drive current of the laser diode LD corresponding to the image data for one page can be accurately calculated.

[0074] The lifetime degree value Y a (where a is an integer of 1 or more) is overwritten on the non-volatile memory 132 every time it is determined whether reuse is possible. Therefore, even when the writing unit 130 is reused a plurality of times, the lifetime degree value Y a can be sequentially passed on, and it is possible to appropriately determine whether the writing unit 130 can be reused using the minimum storage area of the non-volatile memory 132.

[0075] By adding the largest integrated drive current value or the integrated drive current value of the laser diode LD with the highest usage frequency to the integrated drive current value stored in the integrated value storage unit 124, the lifetime degree value Y1 generated by the integrated value conversion unit 125 can be calculated to be larger. As a result, it is possible to prevent the laser diode LD from failing due to its lifetime before the image forming apparatus 100 reaches the end of its life.

[0076] Aspects of the present invention are as follows, for example. <1> A writing unit having a light source, a light source control unit that controls the light source according to a lighting signal, and a non-volatile memory, An image data generation unit that generates image data, A lighting information generation unit that generates the lighting signal and lighting time information corresponding to the lighting signal according to the image data generated by the image data generation unit, A current value integration unit that integrates, as a total drive current value, the drive current used for forming an image corresponding to the image data using the lighting time information and drive current information indicating the drive current of the light source, Based on a lifetime determination instruction, an integrated value conversion unit that converts the total drive current value into an index of the remaining lifetime of the light source using a lifetime current value that is a specification value of the total drive current until the light source reaches the end of its life, and writes the converted index into the non-volatile memory, An image forming apparatus characterized by having the above. <2> The light source control unit outputs the drive current information for each pixel of the image data to the current value integration unit, The current value integration unit calculates a drive current integrated value for each image using the lighting time information, the drive current information, and the number of pixels of the image data, and integrates the total drive current value by adding the calculated drive current integrated value, The image forming apparatus according to <1>, characterized by having the above. <3> Having an integrated value storage unit that stores a drive current integrated value indicating the drive current used for forming the image calculated by the current value integration unit, The current value integration unit adds the integrated value to the integrated value storage unit every time the drive current integrated value is calculated, thereby holding the total drive current value in the integrated value storage unit, The integrated value conversion unit converts the total drive current value held in the integrated value storage unit into the index based on the lifetime determination instruction, The image forming apparatus according to <1> or <2>, characterized by having the above. <4> When the index of the remaining life of the light source is stored in the non-volatile memory, the integrated value conversion unit obtains a new index of the life of the light source based on the total drive current value integrated by the current value integration unit and the index stored in the non-volatile memory, and writes the obtained new index into the non-volatile memory. The image forming apparatus according to any one of <1> to <3>. <5> The writing unit includes a plurality of the light sources. The current value integration unit integrates the total drive current value for each of the plurality of the light sources. The integrated value conversion unit converts the largest total drive current value into an index of the remaining life of the light source. The image forming apparatus according to any one of <1> to <4>. <6> A photoreceptor on which an electrostatic latent image is formed by scanning the light emitted from the light source, A developing device that forms a toner image by developing the electrostatic latent image formed on the photoreceptor, A transfer device that transfers the toner image to a recording medium, A fixing device that fixes the toner image transferred to the recording medium, and having the above. The image forming apparatus according to any one of <1> to <5>. <7> A control method of an image forming apparatus, including a writing unit having a light source, a light source control unit that controls the light source in response to a lighting signal, and a non-volatile memory, an image data generation unit that generates image data, and a lighting information generation unit that generates the lighting signal and lighting time information corresponding to the lighting signal according to the image data generated by the image data generation unit, A current value integration unit included in the image forming apparatus integrates, as a total drive current value, a drive current used in forming an image corresponding to the image data using the lighting time information and drive current information indicating the drive current of the light source. The life conversion unit of the image forming apparatus converts the total drive current value into an index of the remaining life of the light source using the life current value, which is the specification value of the total drive current until the light source reaches the end of its life, based on the life determination instruction, and writes the converted index into the non-volatile memory. A control method for an image forming apparatus, characterized by the above. <8> A control program for an image forming apparatus, comprising: a writing unit having a light source, a light source control unit that controls the light source in response to a lighting signal, a non-volatile memory, an image data generation unit that generates image data, and a lighting information generation unit that generates the lighting signal and lighting time information corresponding to the lighting signal according to the image data generated by the image data generation unit. The current value integration unit of the image forming apparatus integrates the drive current used for forming an image corresponding to the image data as a total drive current value using the lighting time information and drive current information indicating the drive current of the light source. The life conversion unit of the image forming apparatus converts the total drive current value into an index of the remaining life of the light source using the life current value, which is the specification value of the total drive current until the light source reaches the end of its life, based on the life determination instruction, and causes the converted index to be written into the non-volatile memory. A control program for an image forming apparatus, characterized by the above.

[0077] Although the present invention has been described based on each embodiment above, the present invention is not limited to the requirements shown in the above embodiments. In this regard, it can be changed within the scope that does not deviate from the gist of the present invention, and can be appropriately determined according to its application form.

Explanation of symbols

[0078] 10 ADF 20 Image reading unit 30 Image forming unit 40 Paper feeding unit 41 Recording paper cassette 42 Paper feeding device 50 Operation unit 100 Image forming apparatus 110 Writing device 120 Image writing control unit 121 Lighting information generation unit 122 Lifetime conversion unit 123 Current value integration unit 124 Integrated value memory unit 125 Integrated value conversion unit 130 Writing unit 131 LD control unit 132 Non-volatile memory 133 Laser unit 134 Polygon mirror 135(135-1, 135-2) fθ lens 136, 137, 138 Mirrors 141 Cylindrical lens 142(142-1, 142-2) Mirrors 143 Mirror 144(144-1, 144-2) Synchronization detection lens 145(145-1, 145-2) Synchronization detection sensor 150 Photoconductor drum 160 Developing device 170 Intermediate transfer belt 180 Secondary transfer belt 190 Fixing device 200 Control board 210 CPU 220 ROM 230 RAM 240 Flash memory 250 Input interface unit 260 Output interface unit 270 Input / output interface unit 280 Communication interface unit BUS Bus LD Laser diode

Prior art documents

Patent documents

[0079]

Patent Document 1

Claims

1. A writing unit having a light source, a light source control unit that controls the light source according to a lighting signal, and a non-volatile memory, an image data generation unit that generates image data, a lighting information generation unit that generates the lighting signal and lighting time information corresponding to the lighting signal according to the image data generated by the image data generation unit, a current value integration unit that integrates, as a total drive current value, the drive current used for forming an image corresponding to the image data using the lighting time information and drive current information indicating the drive current of the light source, Based on a lifetime determination instruction, an integrated value conversion unit that converts the total drive current value into an index of the remaining lifetime of the light source using a lifetime current value that is a specification value of the total drive current until the light source reaches the end of its life, and writes the converted index into the non-volatile memory, An image forming apparatus characterized by the above.

2. The light source control unit outputs the drive current information for each pixel of the image data to the current value integration unit, The current value integration unit calculates a drive current integrated value for each image using the lighting time information, the drive current information, and the number of pixels of the image data, and integrates the total drive current value by adding the calculated drive current integrated values. The image forming apparatus according to claim 1, characterized by the above.

3. Having an integrated value storage unit that stores a drive current integrated value indicating the drive current used for forming the image calculated by the current value integration unit, The current value integration unit adds the drive current integrated value to the integrated value storage unit every time the drive current integrated value is calculated, thereby holding the total drive current value in the integrated value storage unit, The integrated value conversion unit converts the total drive current value held in the integrated value storage unit into the index based on the lifetime determination instruction. The image forming apparatus according to claim 1 or claim 2, characterized by the above.

4. When an index of the remaining lifetime of the light source is stored in the non-volatile memory, the integrated value conversion unit obtains a new index of the lifetime of the light source based on the total drive current value integrated by the current value integration unit and the index stored in the non-volatile memory, and writes the obtained new index into the non-volatile memory. The image forming apparatus according to claim 1 or claim 2, characterized by the above.

5. The writing unit includes a plurality of the light sources, The current value integration unit integrates the total drive current value for each of the plurality of light sources, The integrated value conversion unit converts the largest total drive current value into an index of the remaining lifetime of the light source. The image forming apparatus according to claim 1 or claim 2, characterized in that.

6. A photoreceptor on which an electrostatic latent image is formed by scanning the light emitted from the light source, A developing device that forms a toner image by developing the electrostatic latent image formed on the photoreceptor, A transfer device that transfers the toner image to a recording medium, A fixing device that fixes the toner image transferred to the recording medium, characterized by having The image forming apparatus according to claim 1 or claim 2, characterized in that.

7. A writing unit having a light source, a light source control unit that controls the light source according to a lighting signal, and a non-volatile memory, an image data generation unit that generates image data, and according to the image data generated by the image data generation unit, A control method for an image forming apparatus having a lighting information generation unit that generates the lighting signal and lighting time information corresponding to the lighting signal, A current value integration unit included in the image forming apparatus integrates, as a total drive current value, the drive current used for forming an image corresponding to the image data using the lighting time information and drive current information indicating the drive current of the light source, A life conversion unit included in the image forming apparatus, based on a life determination instruction, uses a life current value that is a specification value of the total drive current until the light source reaches the end of its life to convert the total drive current value into an index of the remaining life of the light source, and writes the converted index to the non-volatile memory A control method for an image forming apparatus, characterized in that.

8. A control program for an image forming apparatus having a writing unit having a light source, a light source control unit that controls the light source according to a lighting signal, and a non-volatile memory, an image data generation unit that generates image data, and according to the image data generated by the image data generation unit, a lighting information generation unit that generates the lighting signal and lighting time information corresponding to the lighting signal, Causing a current value integration unit included in the image forming apparatus to integrate, as a total drive current value, the drive current used for forming an image corresponding to the image data using the lighting time information and drive current information indicating the drive current of the light source, Causing a life conversion unit included in the image forming apparatus, based on a life determination instruction, to use a life current value that is a specification value of the total drive current until the light source reaches the end of its life to convert the total drive current value into an index of the remaining life of the light source, and write the converted index to the non-volatile memory A control program for an image forming apparatus, characterized in that.

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