JP2000321935A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To widen the utilization extent of recyclable paper and to make efficient use of paper resources by detecting the density of the character/image of the recycled paper and forming an image on the recycled paper when the density is equal to or under a prescribed level. SOLUTION: This image forming device 10 is constituted so that the already recorded paper is recycled and the image is formed on the recycled paper. Besides, it is provided with a read part 15 reading the character/image of the recycled paper, a density detection part 14 detecting the density value of the character/image read by the read part 15 and a CPU 18 comparing the density value detected by the detection part 14 with a previously specified reference value and forming the image on the recycled paper when the density value is equal to or under the reference value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a printer or a copier, and more particularly, to performing test printing by reusing recording paper on which characters and images are recorded. The present invention relates to an image forming apparatus that performs control to determine whether or not to form an image in accordance with the density of a recording sheet.

[0002]

2. Description of the Related Art Conventionally, in image forming apparatuses such as copiers and printers, printing is performed by reducing the printing density with the amount of toner used thinned compared to the amount of toner consumed during normal printing. There is known a so-called toner save technique that effectively utilizes a developed toner. For example, if the printer is set to toner save, it is used for test printing of texts in addition to the purpose of saving development toner.In general, after the text creator checks the printed text, The recording paper is discarded. Further, the recording paper is often discarded due to a low copy density of the copying machine.

Therefore, in consideration of the office environment where recording paper is discarded more and more, techniques for effectively utilizing paper resources have been recently developed and proposed. For example, in Japanese Patent Application Laid-Open No. 9-76590, a "printer" irradiates light onto a recording paper to be printed, detects image information or dirt on the recording paper by reflected light obtained from the light, and sets the detection level to a predetermined value or less. It is disclosed that it is determined whether or not the recording is performed on the detection surface, based on the result of the determination, or recorded on the back surface, or the paper is discharged as it is.

[0004]

However, in the conventional printer as described above, for example, recording paper printed over the entire printing area by the toner save technique or the copy density by a copying machine is low, but the image information is low. However, recording paper or the like printed over the entire printing area has a problem that the image information and the like are at or above a predetermined level, so the range of applications in which reusable printing can be performed is narrowed, and this is not sufficient for effective use of paper resources. Was. In addition, when overwriting printing is performed on reusable paper having image information, there is another problem that the content is difficult to read.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and detects the density of image information of reusable paper, and forms an image on reusable paper when the density is lower than a predetermined level. It is a first object of the present invention to increase the width of usable reusable paper and realize effective use of paper resources. Further, the density of the image information of the reused paper is detected, and when the density is equal to or higher than a predetermined level, the density of the image information on the back surface is further detected. It is a second object of the present invention to increase the width of reusable paper that can be used by forming an image on a paper and to realize effective use of paper resources.

Further, the density of image information on the front / rear side of the reused paper is detected, and when the density is lower than a predetermined level, the image density is controlled to be higher than usual when forming an image on the front / rear side. Accordingly, a third object is to make it easy to determine the recorded content of the image information at the time of reuse even when overwriting printing on the recording paper surface on which the thin image information is printed. Further, the density of the image information on the front / rear sides of the reused paper is detected, and if the density is equal to or higher than a predetermined level on either side, it is meaningless to perform overwrite printing. Thus, a fourth object is to quickly identify unusable reusable paper.

[0007]

In order to achieve the above object, an image forming apparatus according to claim 1 reuses recorded recording paper and forms an image on the reused paper. An image forming apparatus, comprising: reading means for reading image information on the reusable paper; density value detecting means for detecting a density value of the image information read by the reading means; Control means for comparing the density value with a predetermined reference value and forming an image on the reusable paper when the density value is equal to or less than the reference value.

According to the first aspect, the density of the image information on the recording paper (reusable paper) read by the reading means is detected, and the density is compared with a predetermined density value. If it is determined that printing is performed on the fed recording paper (reusable paper), regardless of the character amount or image amount, recording paper printed with the toner save setting or copy paper with low print density can be used. Reuse becomes possible.

According to a second aspect of the present invention, there is provided an image forming apparatus comprising a reversing means for reversing and feeding a recording sheet, and selectively reusing the front and back surfaces of a recorded recording sheet to reuse the same. An image forming apparatus for forming an image on paper, comprising: reading means for reading image information on the front and back surfaces of the reusable paper; and density of image information on the front and back surfaces of the reusable paper read by the reading means. Density value detecting means for detecting a value, comparing the density value of the front surface detected by the density value detecting means with a predetermined reference value, and when the density value is equal to or more than the reference value, further the back surface And a control unit for forming an image on the back surface of the reusable paper if the density value of the back surface is equal to or less than the reference value.

According to the second aspect, the image information of each of the printing surface and the non-printing surface of the recording paper (reusable paper) is read, and the image information of not only the printing surface (the front surface) but also the non-printing surface (the back surface) is read. The density gradation is detected, and if the density of the printing surface is higher than a predetermined level, and if the density of the non-printing surface is lower than the predetermined level, the reversing means is driven to perform printing on the non-printing surface. Even if the printing surface cannot be reused, the reusable printing on the non-printing surface (back surface) can be performed.

According to a third aspect of the present invention, in the image forming apparatus, when forming an image on the reusable paper, the control unit has a higher density than the normal image density. Is set to

According to the third aspect, when the image information of the input print data is printed on the printing surface or the non-printing surface of the recording paper (reusable paper), the printing is performed with a density gradation equal to or higher than a predetermined level. This makes it easy to read the recorded contents of the image information at the time of reusing printing, even when overwriting printing on paper on which thin image information is printed.

Further, in the image forming apparatus according to the present invention, the control means may be arranged so that, when the density value of the front or back surface of the recycled paper detected by the density detection means is equal to or higher than the reference value. Are discharged without performing the image forming operation.

According to the fourth aspect, the density of the image information on the front / rear sides of the reusable paper is detected, and if the density is equal to or higher than a predetermined level on any side, it is meaningless to perform overwriting printing. By discharging the paper without performing image formation, the unusable reusable paper is quickly identified.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an image forming apparatus according to the present invention will be described below in detail with reference to flowcharts showing the configuration of the apparatus and the operation of the apparatus.

FIG. 1 is a block diagram showing an image forming apparatus according to an embodiment of the present invention and a system configuration using the apparatus. FIG. 2 is an explanatory diagram illustrating a schematic configuration of the image forming apparatus in FIG. The image forming apparatus 10 is connected to a host computer 20 via communication means such as a bidirectional communication cable 30. The image forming apparatus 10 in this example forms an image based on an electrophotographic process. As described later, a developing bias control unit 11, an inversion unit 12, a printing unit 13, a density detection unit 14, a reading unit 15, an operation panel 16, a memory 17, a CPU 18, and a data input / output unit 19. Hereinafter, the function of each of these modules will be described.

The developing bias control section 11 is a means for variably controlling the developing bias of the developing roller 3a of the developing section 3 in accordance with a command from the CPU 18 and adjusting the print density by the output voltage. The reversing unit 12 is, as shown in FIG.
This is a reversing mechanism such as a duplex reversing unit that guides the recording paper that has passed through to the conveyance path for duplex reversal just before the discharge roller 7, reverses the recording paper, and re-feeds the paper by the re-feed roller 8.

The printing unit 13 is an image forming means for forming an image based on an electrophotographic process, and includes an optical writing unit 2 for irradiating print data with a laser beam, a photosensitive drum 1 on which an electrostatic latent image is formed, A charging unit for charging the body drum 1,
A developing unit 3 for attaching (developing) toner to the latent image by a developing roller 3a; a transfer / separation unit for transferring and separating an image formed on the photosensitive drum 1 onto recording paper; Modules such as a cleaning unit that removes residual toner, a paper feed unit 4 that feeds out recording paper by a paper feed roller 4a and sends it to a registration roller 5, and a fixing unit 6 that fixes a toner image transferred to the recording paper by applying pressure and heat. Have.

The reading section 15 has a mechanism for irradiating recording paper with light and inputting its reflected light in order to read image information (image density) of the reused paper. The density detecting unit 14 determines the image density of the reusable paper read by the reading unit 15
The density gradation is detected by the data analysis. Operation panel 1
Reference numeral 6 denotes a panel (LCD dot matrix, touch panel, etc.) on which various setting keys (numerical keys, mode keys, etc.) of the image forming apparatus and setting modes, status information, etc. are displayed. The memory 17 is a host computer 20
And temporarily stores data transmitted from the image forming apparatus and various system information of the image forming apparatus.

The CPU 18 is a microprocessor that controls each module constituting the entire image forming apparatus based on a control program. The data input / output unit 19 receives data from the host computer 20 or transmits data from the image forming apparatus to the host computer 2.
0 means to transmit.

The image forming apparatus 10 configured as described above
The print data (including the attached data) sent from the host computer 20 is converted into a control code or the like through a printer driver (not shown) on the host computer 20, and the data input / output unit 19 is transmitted via the bidirectional communication cable 30. Passed to. Also, contrary to this behavior,
Similarly, various data from the data input / output unit 19 is transferred to the printer driver on the host computer 20 via the bidirectional communication cable 30. By transmitting and receiving the various data, the image forming apparatus 10 forms an image of the transmitted image data on a recording sheet.

Next, based on the configuration shown in FIG. 1, the operation (image reading, density gradation detection, image forming operation, etc.) which is a feature of the present invention will be described with reference to the flowcharts shown in FIGS. explain.

FIG. 3 is a flowchart showing a first operation example of the image forming apparatus according to the embodiment of the present invention. When receiving data from the host computer 20, first,
The received data is stored in the memory 17 to form image data (step S11). When the formation of the image data is completed, the printing unit 13 starts feeding recording paper (reusable paper) according to a control command of the CPU 18 (step S12). Subsequently, the reading unit 15 reads the image information of the recording paper and sends it to the density detecting unit 14 (Step S)
13), the density detector 14 performs density analysis to detect a density gradation (step S14).

Subsequently, the CPU 18 compares the detected density gradation with a predetermined value (density gradation ≦ predetermined value) (step S15). If the density gradation is equal to or less than the predetermined value, the CPU 18 reads out the formed image data from the memory 17, sends it to the printing unit 13 (step S16), prints and fixes on the recording paper (step S16). S17), discharge the recording paper (step S1)
8). On the other hand, in step S15, if the detected density gradation is a value larger than the predetermined value, it is determined that printing is not possible, and the transmission of the formed image data is stopped.
The paper is discharged without performing the printing operation on the recording paper.

The above-mentioned density gradation is, for example, a value obtained by averaging the entire density of the recycled paper, or since the image is rarely printed on the periphery (edge) portion of the recording paper, the periphery (edge) portion is used. The average density around the center (effective image area) excluding is used. Alternatively, an average density value excluding the highest value and the lowest value of the density values of the image information, that is, a so-called protruding value may be used. Further, the image formation using the reused paper is executed in the toner save mode set on the operation panel 16.

Therefore, the density of the image information on the recording paper (reusable paper) read by the reading unit 15 is detected, and the density is compared with a predetermined density value. By performing printing on the fed recording paper, reusable printing of recording paper printed with the toner save setting or copy paper with low print density is realized regardless of the character amount and the image amount.

Next, in contrast to the first operation example, when the front side of the recording paper (reusable paper) is not printable, it is determined whether or not printing on the back side is possible. An example of performing printing will be described. FIG. 4 is a flowchart illustrating a second operation example of the image forming apparatus according to the embodiment of the present invention. When data is received from the host computer 20, the received data is first stored in the memory 1 as in FIG.
7 to form image data (step S21). When the formation of the image data is completed, the printing unit 13 starts feeding recording paper (reusable paper) in accordance with a control command of the CPU 18 (step S22). Subsequently, the reading unit 15 reads the image information on the printing surface and the non-printing surface (back surface) of the recording paper and sends the image information to the density detecting unit 14 (Step S23). The density analysis of the back side is performed to detect the density gradation (step S24).

Subsequently, the CPU 18 compares the detected density gradation of the printing surface with a predetermined value (density gradation ≦ predetermined value) (step S25). If the density gradation of the print surface is equal to or less than the predetermined value, the CPU 18 reads the formed image data from the memory 17 and
The recording paper is sent to the printing unit 13 (step S28), and after the recording and fixing on the non-printing surface of the recording paper (step S29), the recording paper is discharged (step S30).

On the other hand, if it is determined in step S25 that the detected density gradation of the printing surface is larger than a predetermined value,
Further, the CPU 18 compares the detected density gradation of the non-printed surface with a predetermined value (density gradation ≦ predetermined value).
(Step S26). Here, if the density gradation on the non-printing surface (back surface) is equal to or lower than the predetermined value level, the CPU 18 determines that printing on the non-printing surface of the recording paper is possible, and drives the reversing unit 12 to change the recording paper. Reverse (Step S2
7).

The CPU 18 reads out the formed image data from the memory 17 and
(Step S28), and after printing and fixing on the non-printing surface of the recording paper (step S29), the recording paper is discharged (step S30). On the other hand, in step S26, if the detected density gradation of the non-printed surface is a value larger than the predetermined value, it is difficult to read the printed image and it becomes useless, so that it is determined that printing is not possible. The sending is stopped, and the sheet is discharged without performing the printing operation on the recording sheet.

Therefore, the image information of each of the printing surface and the non-printing surface of the recording paper (reusable paper) is read, and the density gradation of the image information of not only the printing surface (the front surface) but also the non-printing surface (the back surface) is detected. When the density of the printing surface is higher than a predetermined level, the density of the non-printing surface (back surface) is further determined.
By printing on the non-printing surface by driving the printer 2, the reusable printing on the non-printing surface (back surface) becomes possible even if the printing surface of the recording paper cannot be reused, and the reusability of the paper is improved. Further, a series of operations is clarified by performing a processing operation in a case where reusable printing is not possible on a non-printing surface as well as a printing surface of a recording sheet.

Next, when printing an image on reusable paper,
An example in which printing is performed while controlling the density value to be higher than the normal image density will be described. FIG. 5 is a flowchart illustrating a third operation example of the image forming apparatus according to the embodiment of the present invention. When data is received from the host computer 20,
First, similarly to the above-described operation, the received data is stored in the memory 17 to form image data (step S3).
1). When the formation of the image data is completed, the printing unit 13 starts feeding the recording paper (reusable paper) according to the control command of the CPU 18 (step S32). Subsequently, the reading unit 15 reads the image information of the printing surface and the non-printing surface (back surface) of the recording paper and sends the image information to the density detecting unit 14 (Step S33). The density of the back surface is analyzed to detect the density gradation (step S34).

Subsequently, the CPU 18 compares the detected density gradation of the printing surface with a predetermined value (density gradation ≦ predetermined value) (step S35). If the density gradation on the printing surface is equal to or less than the predetermined value, the CPU 18 instructs the developing bias control unit 11 to control the bias voltage so that the density becomes higher than the normal print density. 11 to adjust the bias at a higher density than usual (step S37). That is, a bias voltage that is somewhat higher than a normal bias voltage is applied to the developing roller 3a of the developing unit 3. Then, the formed image data is read out from the memory 17,
(Step S39), and after printing and fixing on the non-printing surface of the recording paper (Step S40), the recording paper is discharged by the discharge roller 7 (Step S41).

On the other hand, in step S35, if the detected density gradation of the printing surface is a value larger than the predetermined value,
Further, the CPU 18 compares the detected density gradation of the non-printed surface with a predetermined value (density gradation ≦ predetermined value).
(Step S36). Here, if the density gradation on the non-printing surface is equal to or lower than the predetermined value level, the CPU 18 determines that printing on the non-printing surface of the recording paper is possible, and adjusts the developing bias voltage to be higher than usual, and The unit 12 is driven to reverse the recording paper (step S38).

The CPU 18 reads out the formed image data from the memory 17 and
(Step S39), and after printing and fixing on the non-printing surface of the recording paper (step S40), the recording paper is discharged (step S41). On the other hand, in step S36, if the detected density gradation of the non-printing surface is a value larger than the predetermined value, it is difficult to read even if overwritten, so that it is determined that printing is impossible, and the transmission of the formed image data is performed. Is stopped, and the sheet is discharged without performing the printing operation on the recording sheet.

Therefore, when printing the image information of the input print data on the printing surface or the non-printing surface of the recording paper (reusable paper), by printing with a density gradation equal to or higher than a predetermined level, a thin image can be obtained. Even if the information is printed over the paper on which the information is printed, it is possible to easily determine the recorded content of the image information at the time of the reuse printing.

[0037]

As described above, according to the first aspect, when test printing or the like is performed using relatively low-density recording paper that has been printed with toner save, the recording read by the reading unit is performed. The density of image information on paper (reusable paper) is detected, the density is compared with a predetermined density value (reference value), and it is difficult to read even if an image is formed on recording paper having an image density exceeding the predetermined value. The paper is discharged as it is, and if it is determined that the density value is equal to or less than the predetermined value, printing is performed on the fed recording paper. Since reusable printing using low-density copy paper or the like can be performed, the width of the reusable paper is widened, and an image forming apparatus that achieves effective utilization of paper resources can be obtained.

According to the second aspect, when test printing or the like is performed using recording paper having a relatively lower density than normal printed with toner save, the printing surface of the recording paper (reusable paper) / non-printing Reads image information of each side and prints (front side)
Not only is the density gradation of the image information on the non-printing surface (back surface) detected, and if the density on the printing surface (front surface) is higher than a predetermined level, it is useless to print on the printing surface (front surface). Further, if the density level of the non-printing side is determined and the density level is equal to or lower than a predetermined level, the reversing means (double-sided reversing mechanism) is driven to print on the non-printing side. Even if this is not possible, reusable printing on the non-printing surface (back surface) becomes possible, and an image forming apparatus in which the reusability of paper is further improved is obtained.

According to a third aspect, in the first or second aspect, when printing the image information of the input print data on the printing surface or the non-printing surface of the recording paper (reusable paper), for example, By controlling the developing bias to print at a density gradation equal to or higher than a predetermined level, that is, printing with a density higher than the normal image density, even when overwriting printing on paper on which thin image information is printed, It is possible to easily determine the recorded contents of the image information.

According to a fourth aspect, in the first or second aspect, the density of the image information on the front / rear sides of the reusable paper is detected, and if the density is equal to or higher than a predetermined level on any side, the overwriting is performed. There is no meaning that it cannot be read even if printed,
Since the paper is discharged without performing useless image formation, the unusable reusable paper can be quickly distinguished.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an image forming apparatus according to an embodiment of the present invention and a system configuration using the apparatus.

FIG. 2 is an explanatory diagram illustrating a schematic configuration of the image forming apparatus in FIG. 1;

FIG. 3 illustrates a first example of the image forming apparatus according to the embodiment of the invention.
6 is a flowchart showing an operation example of the above.

FIG. 4 illustrates a second example of the image forming apparatus according to the embodiment of the invention.
6 is a flowchart showing an operation example of the above.

FIG. 5 illustrates a third example of the image forming apparatus according to the embodiment of the present disclosure.
6 is a flowchart showing an operation example of the above.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Image forming apparatus 11 Developing bias control part 12 Inversion part 13 Printing part 14 Density detection part 15 Reading part 17 Memory 18 CPU 19 Data input / output part 20 Host computer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/00 108 H04N 1/00 108L F-term (Reference) 2C061 AP04 AQ06 AR03 HH03 HH13 HJ04 HK07 HK11 HN18 KK22 KK25 2H027 DC01 DE02 ED19 5B021 AA01 AA19 FF03 GG02 KK00 LG08 PP01 5C062 AA05 AB08 AB17 AB22 AC04 AC09 AC15 AC21 AC61 BA00 9A001 BB06 DD15 HH23 JJ35 KK42 KK54

Claims (4)

[Claims] 1. An image forming apparatus for reusing recorded recording paper and forming an image on the reused paper, comprising: reading means for reading image information on the reused paper; Density value detecting means for detecting a density value of the image information, comparing the density value detected by the density value detecting means with a predetermined reference value, and when the density value is equal to or less than the reference value, A control unit for forming an image on the reusable paper. 2. A reversing means for reversing and feeding recording paper,
An image forming apparatus that selectively reuses a front surface and a back surface of a recorded recording paper to form an image on the reused paper, wherein a reading unit that reads image information of a front surface and a back surface of the reused paper, The surface of the reusable paper read by the reading means;
Density value detecting means for detecting the density value of the back side image information; comparing the density value of the front surface detected by the density value detecting means with a predetermined reference value, wherein the density value is not less than the reference value Control means for comparing the density value of the back surface with a predetermined reference value and forming an image on the back surface of the reused paper if the density value of the back surface is equal to or less than the reference value. An image forming apparatus characterized in that: 3. The image forming apparatus according to claim 1, wherein the control unit sets, when forming an image on the reusable paper, a density higher than a normal image density as compared with a normal image density. An image forming apparatus according to claim 1. 4. When the density value on the front or back surface of the reusable paper detected by the density detecting means is equal to or higher than the reference value, the control means discharges the paper without performing an image forming operation. The image forming apparatus according to claim 1.