JP3545897B2 - Color image forming equipment - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a color image forming apparatus such as a digital copying machine, a facsimile machine, and a printer.
[0002]
[Prior art]
Generally, in this type of image forming apparatus, since a hard copy is formed on a sheet, a sheet for creating a hard copy is indispensable. Here, the paper is usually subjected to image formation and printing only on one side, excluding double-sided copying. However, in recent years, from the viewpoints of paper dust accompanying the spread of OA equipment, effective utilization of resources, and cost reduction, backing paper (one-sided used paper) is used for copying other than formal documents and printer hard copy. Use cases are increasing. For this reason, one of the paper feed cassettes is also allocated for backing paper.
[0003]
On the other hand, in this type of image forming apparatus, in recent years, full-color machines capable of performing color printing have become widespread, and in addition to conventional black-and-white printing using only black toner, monochromatic printing using single-color toner, as well as monochromatic printing, have been widely used. Full-color printing in which single-color toners are superimposed has also become possible.
[0004]
[Problems to be solved by the invention]
When the above-described backing paper is used in such a full-color compatible image forming apparatus, a full-color image forming process usually requires a transfer process in which toners of a plurality of colors are sequentially superimposed on paper. Therefore, if a backing paper on which toner or the like is already placed on one side is used, wrinkles are likely to occur due to repetition of the transfer process and the like, and this often causes deterioration of image quality and occurrence of jams. As a result, an unsatisfactory printed matter (miscopy) is required, and it is necessary to print again, which is likely to cause inconveniences such as reduced operability.
[0005]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a color image forming apparatus capable of using a backing sheet while minimizing the use of the backing sheet in situations where wrinkles and jams are likely to occur.
[0006]
[Means for Solving the Problems]
The present invention is premised on a color image forming apparatus that includes a plurality of paper feed trays and transfers and forms an image on a paper fed from a selected paper feed tray by an image forming unit. Here, the invention according to claim 1 is provided with a discriminating means for discriminating whether or not the paper stored in each paper feed tray is a backing paper, wherein an image forming mode other than the monochromatic toner print mode is designated, and A warning means is provided for issuing a warning when a paper feed tray containing backing paper is selected. Therefore, when an image forming mode such as a full-color printing mode in which wrinkles and jams are likely to occur when using the backing paper is specified, a warning is issued if the paper feed tray storing the backing paper is selected. Since it is emitted, generation of wrinkles and jams can be suppressed as much as possible. Further, since the warning is kept, the backing paper can be used by the user who is aware of the possibility of occurrence of miscopying.
[0007]
According to a second aspect of the present invention, a discriminating means for discriminating whether or not the paper stored in each paper feed tray is a backing paper is provided. When the selection mode is designated, a paper feed tray selection control means for preferentially selecting a paper feed tray other than the paper feed tray storing the backing paper is provided. Therefore, when an image forming mode such as a full-color print mode in which wrinkles and jams are likely to occur when back paper is used is specified, and when the automatic paper selection mode is specified, the back paper is Since the paper feed tray other than the stored paper feed tray is preferentially selected, the possibility of printing on the back paper is reduced, and the occurrence of wrinkles and jams can be suppressed as much as possible.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to the drawings. The color image forming apparatus according to the present embodiment is applied to a full-color digital copying machine. The apparatus configuration is an existing well-known one, and thus details are omitted. However, the apparatus is schematically configured such that a scanner unit 1 and a printer unit 2 are stacked as schematically shown in FIG. ing. In the scanner section 1, a document pressure plate 3 for pressing a document (not shown) set on a contact glass is provided so as to be openable and closable (or, instead of the document pressure plate 3, an automatic document feeder is provided so as to be openable and closable). . The scanner unit 1 reads the image information of the set document according to the image forming mode, and outputs it as an electric digital signal to the printer unit 2 via an image processing unit (not shown).
[0011]
On the other hand, on the printer unit 2 side, for example, image forming stations (each including a photoreceptor, etc.) for each color toner of yellow, magenta, cyan, and black are arranged in front of a common transfer / transport belt. , Full color printing is possible by repeating a transfer step of sequentially superimposing toner images of each color on the same sheet fed and fed. Of course, if only one color toner is used, monochrome printing can be performed, and if only black toner is used, monochrome printing can be performed. A plurality of paper feed cassettes 4a, 4b, 4c are provided on the upstream side of the transfer / transport belt so as to be selectable manually / automatically. Here, the paper feed cassettes 4a and 4b are mounted inside the printer unit 2 so as to be reversed and fed, and the paper feed cassette 4c is mounted so as to protrude outside the machine. The sheets stored in these sheet cassettes 4a, 4b, 4c are made of the same size or different size as needed.
[0012]
Each of these paper feed cassettes 4a, 4b, and 4c can selectively store back paper. Correspondingly, a back paper detection mechanism 5 for outputting a detection signal used to determine whether or not the stored paper is back paper for each of the paper feed cassettes 4a, 4b, and 4c. 6, 7 are mounted. Here, the paper cassette 4c will be described as an example, and the description will be given with reference to FIGS. When the backing paper is set in the paper feed cassette 4c, the lower surface side is a used surface. Therefore, a plurality of reflective photosensors 8a to 8n are arranged in a distributed manner at the bottom surface side of the paper feed cassette 4c. It is constituted by doing. Each of the reflection-type photo sensors 8a to 8n includes a pair of an LED 9a to 9n and a phototransistor 10a to 10n. For example, taking the reflection type photo sensor 8a as an example, as shown in FIG. 3, when the light from the LED 9a is irradiated so as to face the lowermost sheet P in the sheet feeding cassette 4c, the portion of the sheet P If it is white, it is reflected and received by the phototransistor 10a, but if that part is black, the light is absorbed and not reflected. Therefore, the phototransistor 10a is turned on in the white portion, but not turned on in the black portion. As described above, based on the ratio between the ON signal and the OFF signal (the ratio between the white detection signal and the black detection signal) obtained from the phototransistors 10a to 10n in the plurality of reflective photosensors 8a to 8n, the sheet P is a double-sided blank sheet. Or back paper.
[0013]
The same applies to the paper feed cassettes 4a and 4b. However, when back paper is stored, the used surface thereof is on the upper surface side. Side.
[0014]
More specifically, the detection signals from the back paper detection mechanisms 5, 6, and 7 are taken into the CPU 12 via the I / O port 11 as shown in FIG. It is determined whether the stored paper P is back paper. That is, the function of the determination unit is executed by the determination process by the CPU 12. Such a discrimination method is based on, for example, a discrimination method disclosed in Japanese Patent Application Laid-Open No. 6-255842. Various memories and control objects are connected to the CPU 12 via a bus line or the like. One of them is a start key (copy key), keys for setting various modes, and various information. An operation display unit 13 having a display unit to be connected is connected via the I / O port 11.
[0015]
In such a schematic and basic configuration, even in the full-color digital copying machine of the present embodiment, selection of various image forming modes is performed through a selection operation on the operation display unit 13 and the like, similarly to the existing devices. Is possible. Various image forming modes include, for example, a black-and-white print mode in which printing is performed using only black toner, a single-color toner print mode using only yellow, magenta, and cyan toners, a two-color toner print mode using two-color toner, and all toners. A full-color printing mode is provided by a combination of. In addition, an automatic color selection mode for performing color printing in accordance with the result of reading a document by the scanner unit 1 is also provided. That is, in the automatic color selection mode, since the image depends on the document image, full-color printing may be performed as a result. Alternatively, single-color printing may be performed simply. In addition, regarding paper feeding for copying, in addition to paper feeding from a paper feeding cassette selected by a user, a paper feeding cassette in which paper of a size corresponding to a document size is stored in an automatic paper feeding selection mode (a so-called APS mode). It is also possible to feed paper.
[0016]
Here, in the present embodiment, when a copy operation is to be performed, a function of a discriminating unit, a warning unit, and a paper feed tray selection control unit selectively executed by the CPU 12 according to the setting mode or the like is provided. .
[0017]
Therefore, operation control when the user presses the copy start key will be described with reference to the flowchart shown in FIG. That is, this control is started when the copy start key is pressed, and it is determined whether or not the designated image forming mode is the single-color toner print mode (step S1). In the case of the single-color toner print mode (including the black-and-white print mode), the copy operation is performed according to the designated mode because the double-sided blank paper, the back paper, or the like does not matter.
[0018]
On the other hand, if the mode is not the single-color toner print mode (including the full-color print mode and the automatic color selection mode), it is checked whether the mode related to paper feed is the automatic feed selection mode (S3). . If the automatic paper feed selection mode is not set, it is determined whether or not back paper is set for the paper feed cassette selected and designated by the user based on a detection signal from the back paper detection mechanism corresponding to the paper feed cassette (S4). ). As a result of the determination, there is no particular problem if both sides are blank, so that the copy operation is executed according to the designated mode (S2). On the other hand, if the result of the determination is that the paper in the paper cassette is back paper (Y in S4), a warning to that effect is issued through the operation display unit 13 and the operation of the apparatus is temporarily stopped (S5). The warning in this case is a message such as "Back paper is selected. Please check." And may be accompanied by a buzzer sound or the like. This prompts the user to pay attention to the sheet P, and if the user presses the cancel key or the like, the apparatus returns from the stop state to the standby state, and waits until the copy start key is pressed again after a change in the sheet cassette is specified. When the copy start key is directly pressed, the image forming process is forcibly executed for the paper fed from the paper feed cassette even for the back paper. That is, after the judgment of N in step S1 and the judgment of N in S3, the processing of Y in step S4 is executed as a function of the discriminating means, and the processing of step S5 is executed as the function of the warning means according to the invention of claim 1. Is done. Here, if the result of the determination in step S1 is the case of the automatic color selection mode, the processing of step S5 is executed as the function of the warning means according to the third aspect of the present invention.
[0019]
On the other hand, if the automatic paper feed selection mode is selected for paper feed (Y in S3), a paper feed cassette containing paper of a size corresponding to the original is searched for. The paper cassette in which the paper P is stored is preferentially searched (S6). If there is a corresponding paper cassette (Y in S6), a copy operation is executed according to the designated mode (S2). If the corresponding paper cassette does not exist (N in S6), it is checked whether there is a paper cassette that stores the backing paper of the corresponding size (S7), and the backing paper also has the matching size. If there is no paper (N in S7), it is displayed that there is no compatible size paper, and the operation of the apparatus is temporarily stopped (S8). If there is a suitable size paper for the back paper (Y in S7), the process is not executed as it is, a warning to that effect is issued through the operation display unit 13, and the operation of the apparatus is temporarily stopped (S5). This prompts the user to pay attention to the sheet P, and if the user presses the cancel key or the like, the apparatus returns from the stop state to the standby state, and waits until the copy start key is pressed again after a change in the sheet cassette is specified. When the copy start key is directly pressed, the image forming process is forcibly executed for the paper fed from the paper feed cassette even for the back paper. That is, a series of processes of N in step S1, Y in S3, and Y in S6 are executed as a function of the paper feed tray selection control means according to the second aspect of the present invention. Here, if the result of the determination in step S1 is the case of the automatic color selection mode, the above series of processing is executed as the function of the warning means according to the invention of claim 4.
[0020]
Therefore, according to the present embodiment, when an image forming mode such as a full-color print mode in which wrinkles and jams are likely to occur when back paper is used is specified, the paper feed tray in which the back paper is stored is If it is selected, a warning that the paper is a back sheet is issued through the operation display unit 13, so that the occurrence of wrinkles and jams can be suppressed as much as possible by changing the paper selection. Further, since the warning is kept, the user who is aware of the possibility of the occurrence of a miscopy can use the backing paper as it is. In particular, when the image formation mode by the automatic color selection mode is designated, the result may be a full-color print, but in some cases, a simple color print may be obtained. Considering that there may be a full-color print mode in which wrinkles and jams are likely to occur, a warning is issued if the paper feed tray storing the backing paper is selected. The occurrence of jam can be minimized.
[0021]
On the other hand, when considering the paper selection, a case where an image forming mode such as a full-color print mode in which wrinkles and jams are likely to occur when back paper is used is specified and an automatic paper selection mode is specified In this case, the paper feed tray storing double-sided blank paper is preferentially selected, so that the possibility of printing on the back paper is reduced, and the occurrence of wrinkles and jams can be minimized. In particular, when the image formation mode by the automatic color selection mode is designated, the result may be a full-color print, but in some cases, a simple color print may be obtained. When the automatic paper selection mode is specified, the paper tray containing double-sided blank paper is given priority in consideration of the possibility of the full color print mode in which wrinkles and jams are likely to occur. , The possibility of printing on the backing paper is reduced, and the occurrence of wrinkles and jams can be suppressed as much as possible.
[0022]
In the present embodiment, the determination means is executed by the determination process of the CPU 12 based on the detection signals of the back paper detection mechanisms 5, 6, 7 for each of the paper feed cassettes 4a, 4b, 4c. May be provided as a part of the paper size designating means, and may be executed as a decision means for making a decision based on a signal designated by this function.
[0023]
【The invention's effect】
According to the first aspect of the present invention, when an image forming mode such as a full-color printing mode in which wrinkles and jams are likely to occur when a backing paper is used is specified, a paper feed tray storing the backing paper is selected. If so, a warning is issued, so that the occurrence of wrinkles and jams can be minimized by changing the paper selection or the like.
[0024]
According to the second aspect of the present invention, an image forming mode such as a full-color printing mode in which wrinkles and jams are likely to occur when back paper is used is specified, and an automatic paper selection mode is specified. In this case, priority is given to the paper tray other than the paper tray containing the backing paper, reducing the possibility of printing on the backing paper and minimizing the occurrence of wrinkles and jams. Can be suppressed.
[Brief description of the drawings]
FIG. 1 is a schematic front view of a full-color digital copying machine showing an embodiment of the present invention.
FIG. 2 is a schematic perspective view illustrating an arrangement example of a backing sheet detection mechanism.
FIG. 3 is a side view showing the principle of detection by a reflection type photo sensor.
FIG. 4 is a block diagram schematically showing a hardware configuration.
FIG. 5 is a flowchart illustrating processing control during copying.
[Explanation of symbols]
4a-4c Paper cassette P paper

Claims (2)

In a color image forming apparatus that includes a plurality of paper feed trays and transfers and forms an image in an image forming unit to paper fed from a selected paper feed tray, paper stored in each paper feed tray is A warning unit is provided for determining whether or not the sheet is paper, and a warning is issued when an image forming mode other than the single-color toner print mode is specified and a paper tray containing backing paper is selected. A color image forming apparatus provided with means. In a color image forming apparatus that includes a plurality of paper feed trays and transfers and forms an image in an image forming unit to paper fed from a selected paper feed tray, paper stored in each paper feed tray is A paper tray for storing backing paper when an image forming mode other than the single-color toner print mode is specified and the automatic paper selection mode is specified; A color image forming apparatus comprising a paper feed tray selection control means for preferentially selecting a paper feed tray other than the above.

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