1. A laser printer with self-adaptive printing quality adjustment based on printing quality identification comprises a feeder, a photosensitive drum charging device, a laser, a fixing device and an imaging output device, and is characterized by further comprising a printing quality detector, a printer controller, a photosensitive drum voltage adjustment module, a laser intensity adjustment module, a fixing temperature adjustment module and a fixing pressure adjustment module;

the printing quality detector is used for acquiring a printing image of the laser printer;

the printer controller is used for generating a printing quality problem report according to an original printing image and the printing image, calculating the voltage, the laser intensity, the fixing temperature and the fixing pressure adjustment amount of the photosensitive drum, generating first control information, second control information, third control information and fourth control information according to the calculation result, and then respectively sending the first control information, the second control information, the third control information and the fourth control information to the voltage adjustment module, the laser intensity adjustment module, the fixing temperature adjustment module and the fixing pressure adjustment module of the photosensitive drum;

the photosensitive drum voltage adjusting module is used for adjusting the photosensitive drum voltage according to the first control information of the printer controller;

the laser intensity adjusting module is used for adjusting the laser intensity according to second control information of the printer controller;

the fixing temperature adjusting module is used for adjusting the fixing temperature according to third control information of the printer controller;

and the fixing pressure adjusting module is used for adjusting the fixing pressure according to the fourth control information of the printer controller.

2. The print quality adaptive adjusted laser printer based on print quality identification as claimed in claim 1, wherein the print quality issues are:

if the pixel gray value of the printed image is larger than the set upper limit threshold value, the problem of printing quality is that the printing color is too light; if the pixel gray value of the printed image is smaller than the set lower limit threshold, the problem of printing quality is that the printing color is too deep;

if the consistency of the pixel gray values of the printed image is lower than a set first threshold value, the printing quality problem is uneven printing;

if the difference between the pixel gray value of the printing image and the pixel gray value of the original printing image is larger than the set second threshold, the printing quality problem is incomplete printing.

3. The print quality adaptive adjusted laser printer based on print quality identification according to claim 2, wherein the print quality problem is identified by:

step S10, acquiring a printing image of the laser printer through a printing quality detector;

step S20, setting the grayscale value of the pixel with the grayscale value higher than the set threshold value in the original print image and the print image as 255 respectively, and obtaining a first original print image and a first print image;

step S30, based on the first original print image, respectively performing mesh division on the first original print image and the first print image to obtain a meshed original print image and a meshed print image;

step S40, based on the gray value of each grid in the original grid image is not 255 pixel point distribution to proceed the detection grid priority division;

and step S50, judging whether the current network has printing quality problems according to the priority from high to low, if so, stopping detection and generating a printing quality problem report.

4. The print quality adaptive adjusted laser printer according to claim 3, wherein in step S30, based on the first original print image, the first original print image and the first print image are respectively gridded, and the method comprises:

dividing the first original printing image and the first printing image into a character area, an image area and a line area according to characters, images and lines of the first original printing image;

setting the clustering number according to the character distribution condition in the character area, clustering pixels with the gray value not 255 in the character area, and dividing the character area into grids with the set clustering number;

setting the clustering number according to the image distribution condition in the image area, clustering pixels with the gray scale value not 255 in the image area, and dividing the image area into grids with the set clustering number;

and dividing the line area into a set number of grids according to the line distribution condition in the line area.

5. The print quality adaptive adjusted laser printer based on print quality identification according to claim 3, wherein the step S40 comprises:

acquiring the area of each grid region in the gridded original printing image and the number of pixels with gray values not being 0;

acquiring the pixel density of each grid based on the area of the region and the number of the pixels;

and sequencing the pixel density from high to low, and sequencing the priority of each corresponding grid according to the sequencing of the pixel density.

6. The print quality adaptive laser printer based on print quality recognition according to claim 3, wherein when the original print image is a color image, the original print image is further converted into a grayscale image before performing print quality recognition.

7. The print quality adaptive adjusted laser printer based on print quality identification as claimed in claim 1, wherein said printer controller is further configured to determine whether a current printed page is a waste page based on said print quality information report, and record said waste page.

8. The print quality adaptive adjusted laser printer based on print quality recognition as claimed in claim 7, wherein said printer controller controls said laser printer to reprint the waste pages in the current print job after the current print job is completed.

Background

With the development of printing technology, printers have been widely used in people's life, study, work, etc., and are one of the office equipments commonly used by people. The composition, design structure, control method and adopted components of the control device and components required by the working process of the laser printer are different according to different brands and models, such as: charging photosensitive drums with different polarities; ② the parts adopted for charging the photosensitive drum are different. The existing machine type charges the photosensitive drum in a wire electrode discharge mode, and the existing machine type charges the photosensitive drum by using a charging rubber roller (FCR); the components adopted by transfer printing are different; and fourthly, the exposure forms of the photosensitive drums are different, some models directly scan and expose the photosensitive drums by using scanning mirrors, and some models expose the photosensitive drums by using the scanned reflected laser beams.

Although the printers are different, the working principle is basically the same, and a laser beam emitted by a laser is reflected into an acoustic light deflection modulator through a reflecting mirror; at the same time, the binary image-text dot matrix information sent from computer is transferred into character-form generator from interface to form binary pulse information of required character form, and the signal produced by synchronizer is used for controlling high-frequency oscillator, and then is passed through frequency synthesizer and power amplifier and added onto acousto-optic modulator to modulate laser beam injected from reflector; the modulated light beam is emitted into a multi-surface rotating mirror, and then is focused by a wide-angle focusing mirror and then is emitted onto the surface of a photosensitive drum, so that angular velocity scanning is changed into linear velocity scanning; the surface of the photosensitive drum is charged by a charging electrode to obtain a certain potential, and then an electrostatic latent image is formed on the surface of the selenium drum through exposure of a laser beam carrying image-text image information; the latent image is changed into visible toner image through developing by a magnetic brush developer, the toner is transferred to the common paper under the action of an electric field of a transfer electrode when passing through a transfer area, and finally the characters and images are fused on the paper through a preheating plate and a high-temperature hot roller for fixation; after the image-text information is printed, the cleaning roller removes the toner which is not transferred, the electricity-eliminating lamp removes the residual charge on the drum, and the drum is thoroughly cleaned by the cleaning paper system, so that a new working cycle can be started.

It can be seen that the potential of the photosensitive drum, the intensity and density of the laser beam, and the temperature and pressure of the fixing device all affect the final imaging quality, and after the existing laser printer leaves the factory, the potential of the photosensitive drum, the intensity and density of the laser beam, and the temperature and pressure of the fixing device are difficult to flexibly adjust, and along with the long-term use of the printer, the influence of the abrasion of some devices or other reasons on the photosensitive drum, the laser and the fixing device all cause the imaging quality of the printer to be reduced in different degrees, and waste of consumables is caused.

Disclosure of Invention

In order to solve the above problems in the prior art, namely the problem that the existing laser printer cannot be adjusted in a self-adaptive manner, so that the imaging quality cannot be expected and consumables are wasted, the invention provides a printing quality self-adaptive adjustment laser printer based on printing quality identification, which comprises a feeder, a photosensitive drum charging device, a laser, a fixing device and an imaging output device, and further comprises a printing quality detector, a printer controller, a photosensitive drum voltage adjusting module, a laser intensity adjusting module, a fixing temperature adjusting module and a fixing pressure adjusting module;

the printing quality detector is used for acquiring a printing image of the laser printer;

the printer controller is used for generating a printing quality problem report according to an original printing image and the printing image, calculating the voltage adjustment amount, the laser intensity adjustment amount, the fixing temperature adjustment amount and the fixing pressure adjustment amount of the photosensitive drum, generating first control information, second control information, third control information and fourth control information according to the calculation result, and then respectively sending the first control information, the second control information, the third control information and the fourth control information to the voltage adjustment module, the laser intensity adjustment module, the fixing temperature adjustment module and the fixing pressure adjustment module of the photosensitive drum;

the photosensitive drum voltage adjusting module is used for adjusting the photosensitive drum voltage according to the first control information of the printer controller;

the laser intensity adjusting module is used for adjusting the laser intensity according to second control information of the printer controller;

the fixing temperature adjusting module is used for adjusting the fixing temperature according to third control information of the printer controller;

and the fixing pressure adjusting module is used for adjusting the fixing pressure according to the fourth control information of the printer controller.

In some preferred embodiments, the print quality issue is:

if the pixel gray value of the printed image is larger than the set upper limit threshold value, the problem of printing quality is that the printing color is too light; if the pixel gray value of the printed image is smaller than the set lower limit threshold, the problem of printing quality is that the printing color is too deep;

if the consistency of the pixel gray values of the printed image is lower than a set first threshold value, the printing quality problem is uneven printing;

if the difference between the pixel gray value of the printing image and the pixel gray value of the original printing image is larger than the set second threshold, the printing quality problem is incomplete printing.

In some preferred embodiments, the print quality problem is identified by:

step S10, acquiring a printing image of the laser printer through a printing quality detector;

step S20, setting the grayscale value of the pixel with the grayscale value higher than the set threshold value in the original print image and the print image as 255 respectively, and obtaining a first original print image and a first print image;

step S30, based on the first original print image, respectively performing mesh division on the first original print image and the first print image to obtain a meshed original print image and a meshed print image;

step S40, based on the gray value of each grid in the original grid image is not 255 pixel point distribution to proceed the detection grid priority division;

and step S50, judging whether the current network has printing quality problems according to the priority from high to low, if so, stopping detection and generating a printing quality problem report.

In some preferred embodiments, in step S30, based on the first original print image, the first original print image and the first print image are respectively subjected to mesh division, and the method includes:

dividing the first original printing image and the first printing image into a character area, an image area and a line area according to characters, images and lines of the first original printing image;

setting the clustering number according to the character distribution condition in the character area, clustering pixels with the gray value not 255 in the character area, and dividing the character area into grids with the set clustering number;

setting the clustering number according to the image distribution condition in the image area, clustering pixels with the gray scale value not 255 in the image area, and dividing the image area into grids with the set clustering number;

and dividing the line area into a set number of grids according to the line distribution condition in the line area.

In some preferred embodiments, step S40 includes:

acquiring the area of each grid region in the gridded original printing image and the number of pixels with gray values not being 0;

acquiring the pixel density of each grid based on the area of the region and the number of the pixels;

and sequencing the pixel density from high to low, and sequencing the priority of each corresponding grid according to the sequencing of the pixel density.

In some preferred embodiments, when the original print image is a color image, the original print image needs to be converted into a grayscale image before performing print quality recognition.

In some preferred embodiments, the printer controller is further configured to determine whether the current printed page is a waste page based on the print quality information report, and record the waste page.

In some preferred embodiments, the printer controller controls the laser printer to reprint the waste pages in the current print job after the current print job is completed.

The invention has the beneficial effects that:

(1) the invention discloses a laser printer with print quality self-adaptive adjustment based on print quality identification, which detects the quality of a printed page in real time through a print quality detector, calculates the voltage of a photosensitive drum, the laser intensity, the fixing temperature and the fixing pressure adjustment amount according to the print quality problem if the print quality problem exists, such as too deep or too light print color, uneven printing or incomplete printing, and modulates the voltage of the photosensitive drum, the laser intensity, the fixing temperature and the fixing pressure through an arranged adjustment module to realize the self-adaptive adjustment of the print quality of the laser printer.

(2) According to the laser printer with the printing quality self-adaptive adjustment based on the printing quality identification, when the printing quality identification is carried out, the image is subjected to grid division, the divided grids are subjected to priority ranking, the printing quality identification is carried out according to the sequence of the priority from high to low, once a certain grid is identified to have a printing problem, the whole printing page is taken as a waste page, further judgment is not carried out, and the efficiency of the printing quality identification is effectively improved.

(3) The laser printer with the printing quality self-adaptive adjustment based on the printing quality recognition records the waste printing pages, automatically reprints the waste printing pages after the current printing task is completed, and does not need manual searching and manual intervention, so that the printing efficiency is greatly improved.

Drawings

Other features, objects and advantages of the present application will become more apparent upon reading of the following detailed description of non-limiting embodiments thereof, made with reference to the accompanying drawings in which:

FIG. 1 is a schematic diagram of a component framework of a laser printer with print quality adaptive adjustment based on print quality identification according to the present invention.

Detailed Description

The present application will be described in further detail with reference to the following drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant invention and not restrictive of the invention. It should be noted that, for convenience of description, only the portions related to the related invention are shown in the drawings.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

The invention relates to a laser printer with printing quality self-adaptive adjustment based on printing quality identification, which comprises a feeder, a photosensitive drum charging device, a laser, a fixing device and an imaging output device, and further comprises a printing quality detector, a printer controller, a photosensitive drum voltage adjusting module, a laser intensity adjusting module, a fixing temperature adjusting module and a fixing pressure adjusting module;

the printing quality detector is used for acquiring a printing image of the laser printer;

the printer controller is used for generating a printing quality problem report according to an original printing image and the printing image, calculating the voltage, the laser intensity, the fixing temperature and the fixing pressure adjustment amount of the photosensitive drum, generating first control information, second control information, third control information and fourth control information according to the calculation result, and then respectively sending the first control information, the second control information, the third control information and the fourth control information to the voltage adjustment module, the laser intensity adjustment module, the fixing temperature adjustment module and the fixing pressure adjustment module of the photosensitive drum;

the photosensitive drum voltage adjusting module is used for adjusting the photosensitive drum voltage according to the first control information of the printer controller;

the laser intensity adjusting module is used for adjusting the laser intensity according to second control information of the printer controller;

the fixing temperature adjusting module is used for adjusting the fixing temperature according to third control information of the printer controller;

and the fixing pressure adjusting module is used for adjusting the fixing pressure according to the fourth control information of the printer controller.

In order to more clearly describe the laser printer with print quality adaptive adjustment based on print quality identification according to the present invention, details of the modules in the embodiment of the present invention are described below with reference to fig. 1.

The laser printer with the printing quality self-adaptive adjustment function based on the printing quality identification comprises a feeder, a photosensitive drum charging device, a laser, a fixing device and an imaging output device, and further comprises a printing quality detector, a printer controller, a photosensitive drum voltage adjusting module, a laser intensity adjusting module, a fixing temperature adjusting module and a fixing pressure adjusting module, wherein the modules are described in detail as follows:

and the printing quality detector is used for acquiring a printing image of the laser printer.

In the invention, the image sensor is adopted to obtain the image of the printed image at the outlet of the printer (between the fixation and the paper output, or before the next printing after the paper output), and in order to improve the acquisition precision of the image of the printed image, the image sensor can be also provided with a light source.

And the printer controller is used for generating a printing quality problem report according to an original printing image and the printing image, calculating the voltage, the laser intensity, the fixing temperature and the fixing pressure adjustment amount of the photosensitive drum, generating first control information, second control information, third control information and fourth control information according to the calculation result, and then respectively sending the first control information, the second control information, the third control information and the fourth control information to the voltage adjustment module, the laser intensity adjustment module, the fixing temperature adjustment module and the fixing pressure adjustment module of the photosensitive drum.

Print quality issues include:

if the pixel gray value of the printed image is larger than the set upper limit threshold value, the problem of printing quality is that the printing color is too light; if the pixel gray value of the printed image is smaller than the set lower limit threshold, the problem of printing quality is that the printing color is too deep;

if the consistency of the pixel gray values of the printed image is lower than a set first threshold value, the printing quality problem is uneven printing;

if the difference between the pixel gray value of the printing image and the pixel gray value of the original printing image is larger than the set second threshold, the printing quality problem is incomplete printing.

The shade of the printing color has the following influence factors:

the amount of the base material carbon powder adsorbed (the photosensitive drum potential is too high or too low and/or the laser beam intensity is too high or too low in the case of influencing the base material carbon powder adsorbed amount), the base material adsorption density (the photosensitive drum potential is too high or too low and/or the laser beam intensity is too high or too low and/or the laser beam density is too high or too low in the case of influencing the base material adsorption density), the base material carbon powder permeation amount (the fixing pressure is too low and/or the fixing temperature is too high or too low in the case of influencing the base material carbon powder permeation amount), and the like.

The image has dark or light, that is, the consistency of the pixel gray value of the printed image is low, and the image factors include:

uniformity of toner adsorption to the substrate (unevenness of toner adsorption caused by defects in the substrate, unevenness of toner discharge from the toner outlet, etc.), uniformity of toner penetration to the substrate (unevenness of toner penetration caused by defects in the substrate, unevenness of gap between pressure rollers of the fixing device, high/low temperature due to temperature conduction, etc.), and the like.

Incomplete printing, that is, a certain area appears in a printed page, where the difference between the gray value of a pixel in the printed page and the gray value of a pixel in a corresponding original printed image is greater than a set threshold, which determines that the area is a blank (an area that should be printed but not printed) or a dot (an area that should not be printed or should be printed with different gray values but covered by a large black block), and its image factors include:

defects in the substrate, uneven gap between the pressure rollers of the fixing device, high and low temperatures due to temperature conduction, deviation of the laser beam, and the like may cause problems of incomplete printing.

The print quality identification needs to be performed on the basis of comparing the image of the print image with the original print image, and therefore, if the original print image is a color image, the original print image needs to be converted into a grayscale image, that is, the color image of the original print image is converted into a grayscale image through graying, and the image graying method includes a component method, a maximum value method, an average value method, a weighted average method and the like.

The identification method of the printing quality problem comprises the following steps:

and step S10, acquiring a printing image of the laser printer through a printing quality detector.

Step S20, setting the grayscale value of the pixel with the grayscale value higher than the set threshold value in the original print image and the print image as 255, respectively, to obtain a first original print image and a first print image.

The reason why the gray value of the pixel with the gray value higher than the set threshold is set to 255 (i.e. adjusted to pure white) is to eliminate the blank parts in the image of the printed image and the original printed image so as to avoid the influence of the pixels when the subsequent grid division is performed for clustering or density calculation and quantity statistics (some blank parts, the pixels in the image of the printed image and the original printed image may be different gray values close to pure white, and if the part of pixels are not eliminated, the direct clustering or density calculation and quantity statistics have no meaning, because each area of the scanned image has the same pixel density and distribution, and the same number of pixels only differs in the gray value).

In one embodiment of the present invention, the blank area of the image is extracted by the blank area extraction model, and the gray value of the pixel is 255, so as to obtain the first original print image and the first print image, and the specific method thereof includes:

acquiring characters and/or images with lines with different shapes and sizes as a training sample set of the model, and acquiring corresponding real area attributes (the attributes comprise blanks, characters, images and lines) in the training sample as labels; the blank area extraction model is constructed based on a neural network, and a cross entropy loss function is used as a loss function of the model;

randomly selecting a batch of training samples and labels corresponding to the training samples, and obtaining prediction area attributes corresponding to the training samples through a model;

calculating a cross entropy loss value between the predicted region attribute and the label through a cross entropy function, and performing iterative training on the model in a descending direction of the cross entropy loss value until the cross entropy loss value is lower than a set value or reaches a set training frequency to obtain a trained blank region extraction model;

and respectively extracting blank areas in the original printing image and the printing image through the trained blank area extraction model, and setting the pixel gray value in the blank areas to be 255 to obtain a first original printing image and a first printing image.

Besides the cross entropy function, the model can be trained by other preset loss functions, and the preset loss functions are shown as formula (1):

formula (1)

Wherein the content of the first and second substances,representing a locationiThe label of the pixel of the image,representing a locationiThe pixel prediction tag is processed and then the pixel prediction tag is processed,representing a position in an imageiThe gradient of the pixels at (a) is,Trepresents a transposition of the matrix by a phase-shifting device,H、Wrepresenting the height and width of the pixels of the image respectively,the number of the image pixels is the number of the image pixels,to characterizeLoss andin the total lossThe weight parameter of medium importance.

Step S30, based on the first original print image, respectively performing mesh division on the first original print image and the first print image, to obtain a meshed original print image and a meshed print image.

The method for grid division comprises the following steps:

dividing the first original printing image and the first printing image into a character area, an image area and a line area according to characters, images and lines of the first original printing image;

setting the clustering number according to the character distribution condition in the character area, clustering pixels with the gray value not 255 in the character area, and dividing the character area into grids with the set clustering number;

setting the clustering number according to the image distribution condition in the image area, clustering pixels with the gray scale value not 255 in the image area, and dividing the image area into grids with the set clustering number;

and dividing the line area into a set number of grids according to the line distribution condition in the line area.

In addition to the above-mentioned mesh division method, it may also be selected to perform a set number of mesh divisions directly according to the number of pixels, specifically including:

respectively counting the number of pixels of which the number is not 255 in each area, and setting the number of grids in each area according to the number of the pixels;

each region is divided into a plurality of grids having the same number of pixels (or different by 1) according to the set number.

Step S40, performing detection mesh prioritization based on the distribution of pixel points for which the gradation value of each mesh is not 255 in the gridded original print image:

acquiring the area of each grid region in the gridded original printing image and the number of pixels with gray values not being 0;

acquiring the pixel density of each grid based on the area of the region and the number of the pixels;

and sequencing the pixel density from high to low, and sequencing the priority of each corresponding grid according to the sequencing of the pixel density.

And step S50, judging whether the current network has printing quality problems according to the priority from high to low, if so, stopping detection and generating a printing quality problem report.

The photosensitive drum voltage adjusting module is used for adjusting the photosensitive drum voltage according to first control information of the printer controller;

the laser intensity adjusting module is used for adjusting the laser intensity according to second control information of the printer controller;

the fixing temperature adjusting module is used for adjusting the fixing temperature according to third control information of the printer controller;

and the fixing pressure adjusting module is used for adjusting the fixing pressure according to the fourth control information of the printer controller.

The printer controller is also used for judging whether the current printing page is a waste page or not based on the printing quality information report, recording the waste page, and controlling the laser printer to reprint the waste page in the current printing task after the current printing task is finished.

Although the foregoing embodiments describe the steps in the above sequential order, those skilled in the art will understand that, in order to achieve the effect of the present embodiments, the steps may not be executed in such an order, and may be executed simultaneously (in parallel) or in an inverse order, and these simple variations are within the scope of the present invention.

It should be noted that, the laser printer with print quality adaptive adjustment based on print quality identification provided in the foregoing embodiment is only illustrated by the division of the above functional modules, and in practical applications, the above function allocation may be completed by different functional modules according to needs, that is, the modules in the embodiment of the present invention are further decomposed or combined, for example, the modules in the foregoing embodiment may be combined into one module, or may be further split into multiple sub-modules, so as to complete all or part of the above described functions. The names of the modules involved in the embodiments of the present invention are only for distinguishing the modules, and are not to be construed as unduly limiting the present invention.

The terms "first," "second," and the like are used for distinguishing between similar elements and not necessarily for describing or implying a particular order or sequence.

The terms "comprises," "comprising," or any other similar term are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

So far, the technical solutions of the present invention have been described in connection with the preferred embodiments shown in the drawings, but it is easily understood by those skilled in the art that the scope of the present invention is obviously not limited to these specific embodiments. Equivalent changes or substitutions of related technical features can be made by those skilled in the art without departing from the principle of the invention, and the technical scheme after the changes or substitutions can fall into the protection scope of the invention.