JPH09185208A - Electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease an amount of toner at the time of color image formation by providing a control part capable of executing a toner save mode which decreases the amount of attaching toner at least in one color. SOLUTION: An engine CPU 111 for controlling a printer engine executes the toner save mode so that the amount of attaching toner decreases at least in one color out of a plurality of recording colors. In this toner save mode, to decrease the amount of toner attachment, it is preferable that the number of rotations of a developing sleeve be controlled so as to change from an ordinary value. When the toner save mode is specified from the console panel of an operation display part 102, a controller 101 transmits an instruction signal to the engine CPU 111, which sets the developing sleeve of a developing part 131 for the number of rotations corresponding to the specified mode. The amount of attaching toner can be made small by reducing the number of rotations of the developing sleeve, thereby making the ratio of circumferential speeds between the developing sleeve and the photoreceptive drum 141 small.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic recording apparatus for copying an image on a transfer paper by forming a latent image on a photoconductor, and more particularly to an electronic image forming apparatus for forming a color image by toner of plural recording colors. The present invention relates to a photographic recording device.

[0002]

2. Description of the Related Art Generally, in an electrophotographic image forming apparatus (electrophotographic recording apparatus), an image is converted into an electric signal (image signal) according to the density of image information (original image) of a document,
An electrostatic latent image is formed on the photosensitive drum by using a laser beam or the like according to the image signal.

Then, the electrostatic latent image is developed into a toner image and then transferred to a transfer sheet, and the toner image on the transfer sheet is heated and fused and fixed by a heater of a fixing device. As this electrophotographic recording device, an electrophotographic recording device that forms a color image with a plurality of recording colors (for example, a combination of yellow, magenta, and cyan, or a combination of yellow, magenta, cyan, and black) is put on the market. Has been done.

[0004]

A general monochrome electrophotographic recording apparatus has a printing mode called a toner save mode for test printing for confirmation of layout and the like, and a mode for reducing the toner amount. Exists.

In the monochrome toner save mode, for example, a method of extracting and printing only the edge of a print portion, a method of thinning out main scanning lines, and the like are known. On the other hand, in a color electrophotographic recording apparatus, the cost of toner is very high, and the print per sheet becomes expensive.

However, a method corresponding to the toner save mode in monochrome described above does not exist in printing a color image. This is because it is necessary to check including the color tone. Therefore, there is no method other than actually outputting an expensive color print to check the layout.

Further, as described above, it is not desirable that the color tone changes in the toner save mode because checking the color tone is also an important issue in color images.

Therefore, an object of the present invention is to provide an electrophotographic recording apparatus having a toner save mode for reducing the amount of toner when forming a color image.

[0009]

[Means for Solving the Problems]

(1) That is, the invention for solving the above-mentioned problems is an electrophotographic recording apparatus that forms an image with toner of a plurality of recording colors, and is capable of executing a toner save mode in which the toner adhesion amount of at least one color is reduced. An electrophotographic recording apparatus comprising a control unit.

In the invention of the electrophotographic recording apparatus, the toner save mode is executed so as to reduce the toner adhesion amount for at least one of the plurality of recording colors. (2) Further, in order to reduce the toner adhesion amount, it is preferable that the control unit controls the number of rotations of the developing sleeve in the toner save mode so as to be changed from a normal value.

In the invention of the electrophotographic recording apparatus, the toner save mode is executed for at least one of the plurality of recording colors by controlling the rotation speed of the developing sleeve so as to reduce the toner adhesion amount.

(3) Further, in the toner save mode, the above-mentioned control unit can independently control the modulation factor when the pulse width of the image signal for driving the writing means is modulated for each recording color. It is preferable in reducing the amount of adhesion.

In the invention of this electrophotographic recording apparatus, the toner save mode is executed so as to reduce the toner adhesion amount by controlling the modulation degree of the pulse width modulation for at least one of the plurality of recording colors.

(4) The invention for solving the above-mentioned problems is an electrophotographic recording apparatus for forming an image with toner of a plurality of recording colors, which is obtained by performing a logical operation of image data and a specific pattern. A logical operation means for generating an image signal for driving the writing means for at least one color from the result of the logical operation; and a control section for causing the logical operation means to execute a toner save mode for reducing the toner adhesion amount of at least one color. An electrophotographic recording device comprising:

In the invention of the electrophotographic recording apparatus, the number of pixels to be recorded is reduced for at least one of the plurality of recording colors by the logical operation result of the image signal and the specific pattern, and the toner adhesion amount is effectively. Toner save mode is executed so as to decrease.

It is to be noted that, in an electrophotographic recording apparatus in which at least yellow, magenta, and cyan are used as the plurality of recording colors, and an image is formed by toners of these colors, the logical operation means includes yellow, magenta, and cyan. It is preferable to use the same pattern for each color as the specific pattern for each color in order to confirm the color shift of the overlapping colors.

Further, it is preferable for the stability of the operation that a switching unit for switching between the result of the logical operation and the image signal not subjected to the logical operation is provided and switching is performed as necessary.
Further, in order to realize a reliable operation, it is possible to provide a switching unit that switches the logical operation result and the image signal that is not logically operated based on an instruction signal from the outside, and perform switching in accordance with the instruction signal from the outside. preferable.

Further, a reliable operation is provided by providing a switching unit for switching the logical operation result and the image signal which is not logically operated based on the instruction signal from the operation unit, and performing the switching in accordance with the instruction signal from the operation unit. It is preferable for realizing.

Further, as the above-mentioned logical operation means, a means for generating an image signal for driving a laser diode from a logical operation result obtained by performing a logical operation of image data and a specific pattern by a logical product for each bit, It is preferable for executing stable logical operations.

Further, as the above-mentioned logical operation means, a means for extracting a logical operation for two or more consecutive pixels from the image data to perform a logical operation and generating an image signal for driving a laser diode from the result of the logical operation is It is preferable for confirming the deviation.

Therefore, the electrophotographic recording apparatus as described above can reduce the amount of toner when forming a color image. (5) Further, the invention which solves the above-mentioned problems is an electrophotographic recording apparatus for forming an image with toner of a plurality of recording colors, and a toner save mode for reducing the toner adhesion amount of at least one color can be executed. In the toner save mode, the control unit controls the number of rotations of the developing sleeve, and the modulation factor when the pulse width modulation of the image signal for driving the writing unit is independently performed for each recording color. The present invention is an electrophotographic recording apparatus characterized in that the toner adhesion amount is reduced by controlling

In the invention of the electrophotographic recording apparatus, the toner adhesion amount is reduced by controlling the rotation speed of the developing sleeve and the modulation degree of the pulse width modulation for at least one of the plurality of recording colors. Toner save mode is executed.

(6) Further, the invention for solving the above-mentioned problems is an electrophotographic recording apparatus for forming an image with a plurality of recording color toners, and a toner save mode for reducing the toner adhesion amount of at least one color is provided. Executable control unit,
A logical operation means for generating an image signal for driving the writing means for at least one color from a logical operation result obtained by performing a logical operation on the image data and the specific pattern, and the control section, in the toner save mode, An electrophotographic recording apparatus characterized by controlling the number of revolutions of a developing sleeve and controlling a logical operation of the logical operation means so as to reduce the toner adhesion amount of at least one color.

In the invention of the electrophotographic recording apparatus, the toner adhesion amount is reduced for at least one of the plurality of recording colors by the control by the logical operation of the image signal and the specific pattern and the rotation speed of the developing sleeve. The toner save mode is executed as described above.

(7) Further, the invention for solving the above-mentioned problems is an electrophotographic recording apparatus for forming an image with toners of a plurality of recording colors, and a toner save mode for reducing the toner adhesion amount of at least one color is provided. Executable control unit,
A logical operation means for generating an image signal for driving the writing means for at least one color from a logical operation result obtained by performing a logical operation on the image data and the specific pattern, and the control section, in the toner save mode, Toner adhesion of at least one color is achieved by controlling the modulation degree when the pulse width modulation of the image signal for driving the writing means is independently performed for each recording color and by controlling the logical operation of the logical operation means. The electrophotographic recording apparatus is characterized by controlling so as to reduce the amount.

In the invention of this electrophotographic recording apparatus, the toner adhesion amount is reduced for at least one of the plurality of recording colors by the control by the logical operation of the image signal and the specific pattern and the control of the pulse width modulation. Toner save mode is executed.

(8) When the pulse width modulation of the image signal is independently performed for each recording color in the toner save mode in the toner save mode, the control unit makes the duty ratio smaller than in the normal mode. , (5) or (7) is preferable.

(9) In the toner save mode, the above-mentioned control unit can control the modulation factor when the pulse width is independently modulated for each recording color for the image signal after color correction. Is preferable in the electrophotographic recording apparatus described in any one of (3), (5), and (7) above.

(10) In the toner save mode, the above-mentioned control unit controls the power of the writing unit according to the environmental conditions, and the power of the controlled writing unit is used as a reference for the image signal independently for each recording color. It is preferable in the electrophotographic recording apparatus according to any one of (3), (5), and (7) described above to control the modulation degree when performing pulse width modulation.

(11) An electrophotographic recording apparatus which uses at least yellow, magenta and cyan as a plurality of recording colors and forms an image with toner of these colors, wherein the logical operation means is yellow, magenta, It is preferable for the electrophotographic recording apparatus according to any one of (4), (6), and (7) that each cyan color is provided and that the same pattern is used as the specific pattern for each color.

(12) An electrophotographic recording apparatus for forming an image with toner of a plurality of recording colors, wherein an image signal for driving the writing means is obtained from a logical operation result obtained by performing a logical operation on image data and a specific pattern. It is described in any one of (4), (6) or (7) that a logical operation means for generating a color is provided for at least one color, and a switching unit for switching a logical operation result and an image signal that is not logically operated is provided. Is preferable for the electrophotographic recording device.

(13) An electrophotographic recording apparatus for forming an image with toner of a plurality of recording colors, wherein an image signal for driving the writing means is obtained from a logical operation result obtained by performing a logical operation on image data and a specific pattern. (4), which has a logical operation unit for generating at least one color, and a switching unit for switching the logical operation result and the image signal which is not logically operated based on an instruction signal from the outside.
It is preferable in the electrophotographic recording device according to (6) or (7).

(14) An electrophotographic recording apparatus for forming an image with toner of a plurality of recording colors, wherein an image signal for driving the writing means is obtained from a logical operation result obtained by performing a logical operation on image data and a specific pattern. (4), which has a logical operation means for generating at least one color, and a switching section which switches a logical operation result and an image signal which is not logically operated based on an instruction signal from the operation section.
It is preferable in the electrophotographic recording device according to (6) or (7).

(15) An electrophotographic recording apparatus for forming an image with toner of a plurality of recording colors, wherein a logical operation of image data and a specific pattern is performed by a logical product of each bit to obtain a logical operation result. It is preferable in the electrophotographic recording apparatus according to any one of (4), (6) or (7) that at least one color is provided with a logical operation means for generating an image signal for driving the writing means.

(16) An electrophotographic recording apparatus for forming an image with toners of a plurality of recording colors, wherein a logical operation is performed on image data by extracting two or more consecutive pixels and performing a logical operation, and writing from the result of the logical operation. It is preferable in the electrophotographic recording apparatus described in any of (4), (6) or (7) that at least one color is provided with a logical operation means for generating an image signal for driving the means.

(17) Further, the above control section can execute the toner save mode in response to an instruction signal from the operation section of the electrophotographic recording apparatus or an external device. (18) Note that it is effective for the above-described control unit to continue executing the toner save mode until the transfer sheet is completely discharged, as a countermeasure against a transfer sheet jam or the like.

(19) Further, the above-mentioned control section surely executes the toner save mode by returning from the toner save mode to the normal mode after the transfer paper on which the image is formed in the toner save mode is completely discharged. It is effective for doing and executing the normal mode.

(20) Further, the above-mentioned control section, after discharging the transfer sheet on which the image is formed in the toner save mode,
Returning to the normal mode either manually or automatically is effective for surely executing the toner save mode and for executing the normal mode.

(21) Further, the above-mentioned control section, after discharging the transfer paper on which the image is formed in the toner save mode,
It is effective for surely executing the toner save mode and for executing the normal mode to return to the normal mode according to the selected side of the manual operation and the automatic operation.

[0040]

Embodiments of the present invention will be described below in detail. <Structure> FIG. 1 is a functional block diagram showing a schematic structure of a main part of an electrophotographic recording apparatus according to an embodiment of the present invention.

In FIG. 1, the host 1 is a computer that sends various images to the electrophotographic recording apparatus 100 using PDL (page description language) or the like. The electrophotographic recording apparatus 100 is a printer that receives image information from the host 1 and forms an image on a transfer sheet with a plurality of recording colors.

The controller 101 receives an instruction signal and image information from the host 1 and an instruction signal from the operation display unit 102, and develops a bitmap (RG described in PDL or the like).
From the image information of B, the recording color for each page (YMC or YMC
(K) processing for generating image data of bitmap), gamma correction, and various controls. The operation display unit 102 constitutes an operation panel that receives an operation and a display unit that performs a display in the electrophotographic recording apparatus 100, and exchanges data and commands with the controller 101.

The bit map developing memory 103 stores each recording color (YM) which has been bit map expanded by the controller 101.
This is a memory for storing page-by-page image data for each C or YMCK). The selector 104 is a means for selectively passing the image data expanded into the bitmap for each recording color.

The engine CPU 111 is a CPU that controls the printer engine section of the electrophotographic recording apparatus. PW
The M section 121 is means for pulse-width-modulating the image data that has passed through the selector 104 to generate an image signal for driving a laser diode. The laser diode 122 is an image writing unit that emits a laser beam according to an image signal. The developing unit 131 is a unit that develops the electrostatic latent image on the photosensitive drum into a toner image, and the rotation speed of the developing sleeve is controlled by an instruction from the engine CPU 111. The photoconductor drum 141 is an image carrier on which an electrostatic latent image is generated by writing the laser diode 122.

<Operation> The operation of the embodiment of the electrophotographic recording apparatus configured as described above is as follows. First, the first embodiment will be described with reference to the flowchart in FIG.

Operation display section 10 of electrophotographic recording apparatus 100
When the toner save mode is designated from the operation panel of No. 2 (S1 in FIG. 2), the controller 101 receiving this designation sends an instruction signal corresponding to the mode designation to the engine C.
It is transmitted to the PU 111 (FIG. 2S2).

When the engine CPU 111 receives the mode designation instruction signal, it sets the number of rotations corresponding to the mode designation to the developing sleeve of the developing unit 131 (FIG. 2S).
4). Here, the relationship between the rotation speed of the developing sleeve and the toner save mode will be described with reference to FIG.

FIG. 3 is a characteristic diagram showing a correspondence relationship between the peripheral speed ratio and the toner adhesion amount. Here, the peripheral speed ratio is a ratio (Vs / Vp) between the rotational peripheral speed Vs of the developing sleeve and the rotational peripheral speed Vp of the photosensitive drum. Generally, since the rotation speed of the photosensitive drum is constant, the peripheral speed ratio is changed by changing the rotation speed of the developing sleeve. In addition, the toner adhesion amount M /
A means the toner adhesion amount (mg / cm ² ) per unit area of the photosensitive drum 141 after development.

In a normal electrophotographic recording apparatus, this peripheral speed ratio operates within the range of 2.5 to 3.0. Therefore, the toner adhesion amount can be reduced by lowering the rotational speed of the developing sleeve to reduce the peripheral speed ratio. Therefore, according to this characteristic diagram, the rotation speed of the developing sleeve is determined so that a desired toner adhesion amount is obtained in the toner save mode.

With respect to the number of rotations of the developing sleeve, since the characteristics shown in FIG. 3 are different for each color (YMCK), the toner adhesion amount so as not to change the color tone in the color print is obtained for each color, and then each color is determined. It is preferable to determine the rotation speed of the developing sleeve. Then, the number of rotations of the developing sleeve of each color in the toner save mode may be held in advance in the engine CPU 111 or in a table or the like accessible from the engine CPU 111.

The characteristics shown in FIG. 3 may change depending on the environmental conditions (temperature, humidity), and when the peripheral speed ratio is corrected according to the environmental conditions, the toner save mode is set at the time of the correction. It is also possible.

When the preparation of each unit is completed and the print data is sent from the host 1, printing is executed according to the instructions from the controller 101 and the engine CPU 111 (S7 to S8 in FIG. 2).

After the transfer paper is ejected, the engine CPU 111 sets the developing sleeve rotation speed to a normal value (S9 in FIG. 2). Even when the printing operation is canceled by the operation panel of the operation display unit 102 or the host 1 before the start of printing (S6 in FIG. 2), the engine CPU 111 sets the developing sleeve rotation speed to the normal value in preparation for the next printing. (FIG. 2S9).

When a jam (JAM) occurs during printing (S10 in FIG. 2), the printing operation (operation in the toner save mode) is performed by instructing online / printing again after removing the jammed paper. To be executed. That is, the mode state is maintained until the printing operation is properly completed.

By the operation for reducing the rotation speed of the developing sleeve as described above, when the toner save mode is selected, it is possible to realize a light print in which the toner adhesion amount is suppressed. Further, unlike the monochrome edge-only print, since the color print is performed with the toner of the light color as a whole, the layout and the color arrangement of the print can be confirmed. Further, by independently determining the number of rotations of the developing sleeve for each color so that the color tone does not change, it is possible to check the color tone even in the toner save mode. Further, since the state of the toner save mode is maintained until the transfer paper is completely discharged, the toner save mode can be continuously printed even when reprinting is performed in the case of a transfer paper jam or the like. The toner usage amount can be suppressed by executing the toner save mode for at least one color instead of for all the colors.

<Operation> Next, the second embodiment will be described with reference to the flowchart of FIG.

When the toner save mode is designated by the operation of the host 1 (FIG. 4S1), the controller 101 (FIG. 4S2) receiving this designation transmits an instruction signal corresponding to the mode designation to the engine CPU 111 (FIG. 4). 4S3).

When the engine CPU 111 receives the mode designation instruction signal, the engine CPU 111 sets the number of revolutions corresponding to the mode designation to the developing sleeve of the developing section 131 (FIG. 4S).
5). That is, according to the characteristic diagram of FIG. 3 described above, the rotation speed of the developing sleeve is determined so that a desired toner adhesion amount is obtained in the toner save mode.

The characteristics shown in FIG. 3 may change depending on the environmental conditions (temperature, humidity), and when the peripheral speed ratio is corrected according to the environmental conditions, the toner save mode is set during the correction. It is also possible.

When the preparation of each unit is completed and the print data is sent from the host 1, printing is executed according to the instructions from the controller 101 and the engine CPU 111 (FIGS. 4 S8 to S9).

After the transfer paper is ejected, the engine CPU 111 sets the developing sleeve rotation speed to the normal value (S10 in FIG. 4). Even when the printing operation is canceled by the operation panel of the operation display unit 102 or the host 1 before the start of printing (S7 in FIG. 4), the engine CPU 111 sets the developing sleeve rotation speed to the normal value in preparation for the next printing. (FIG. 4S10).

If a jam (JAM) occurs during printing (S11 in FIG. 4), the print operation (operation in the toner save mode) can be performed by instructing online / print again after removing the jammed paper. To be executed. That is, the mode state is maintained until the printing operation is properly completed.

By the operation of lowering the rotation speed of the developing sleeve in accordance with the instruction from the host 1 as described above, when the toner save mode is selected, it is possible to realize a light print in which the toner adhesion amount is suppressed. Further, unlike the monochrome edge-only print, since the color print is performed with the toner of the light color as a whole, the layout and the color arrangement of the print can be confirmed. Further, by independently determining the number of rotations of the developing sleeve for each color so that the color tone does not change, it is possible to check the color tone even in the toner save mode. Further, since the state of the toner save mode is maintained until the transfer paper is completely discharged, the toner save mode can be continuously printed even when reprinting is performed in the case of a transfer paper jam or the like. The toner usage amount can be suppressed by executing the toner save mode for at least one color instead of for all the colors.

<Structure> FIG. 5 is a functional block diagram showing a schematic structure of a main part of the electrophotographic recording apparatus of the second structure example of the embodiment of the present invention.

In FIG. 5, the host 1 is a computer that sends various images to the electrophotographic recording apparatus 100 using PDL (Page Description Language) or the like. The electrophotographic recording apparatus 100 is a printer that receives image information from the host 1 and forms an image on a transfer sheet with a plurality of recording colors.

The controller 101 receives an instruction signal and image information from the host 1 and an instruction signal from the operation display unit 102, and develops a bitmap (RG described in PDL or the like).
From the image information of B, the recording color for each page (YMC or YMC
(K) processing for generating image data of bitmap) and various control units. The operation display unit 102 constitutes an operation panel that receives an operation and a display unit that performs a display in the electrophotographic recording apparatus 100, and exchanges data and commands with the controller 101.

The bitmap developing memory 103 stores each recording color (YM
This is a memory for storing page-by-page image data for each C or YMCK). The color correction means 104 'is a color correction means for selectively passing the image data expanded in the bitmap for each recording color and for performing secondary color correction.

This secondary color correction is a process also called KNC correction, and by correcting the image signal corresponding to the toner of the upper layer by the overlapping degree of the toner of each color on the photosensitive drum, the toner adhesion amount of the upper layer is corrected. Is a color correction process such that The gamma correction unit 105 is a correction unit that performs gamma correction.

The engine CPU 111 is a CPU that controls the printer engine section of the electrophotographic recording apparatus. PW
The M section 121 is means for pulse-width-modulating the image data that has passed through the gamma correction section 105 to generate an image signal for driving a laser diode. The laser diode 122 is an image writing unit that emits a laser beam according to an image signal. The developing unit 131 is a unit that develops the electrostatic latent image on the photosensitive drum into a toner image, and includes the engine CPU 111.
The rotation speed of the developing sleeve is controlled according to the instruction from.
The photoconductor drum 141 is an image carrier on which an electrostatic latent image is generated by writing the laser diode 122.

<Operation> Next, a third embodiment will be described with reference to the flowchart of FIG.

Operation of host 1 or operation display unit 102
When the toner save mode is designated by (S1 in FIG. 6), the controller 101 receiving this designation transmits an instruction signal corresponding to the mode designation to the engine CPU 111 (S2 in FIG. 6). When the toner save mode is designated by the operation of the host 1, the host 1 notifies the controller 101 as predetermined data or command.

When the engine CPU 111 receives the mode designation instruction signal, it sets the pulse width modulation coefficient corresponding to the mode designation in the PWM unit 121 (S4 in FIG. 6).
Here, as shown in the characteristic diagram of FIG. 7, in the relationship between the modulation degree and the toner density D on the photosensitive drum 141, the PWM
In the region of less than 10% and PWM 90 to 100%, the density D does not change linearly. Therefore, in the toner save mode, the normal solid is 100% PWM.
Then, it is preferable to multiply by a value of 0.1 to 0.9 as the pulse width modulation coefficient so that the PWM becomes 20% to 80%. Further, from the relationship between the color reproducibility and the amount of toner used, 0.4 to 0.6 is more preferable. For example, when 0.5 is used as the pulse width modulation coefficient, it means that the toner usage amount is about half that in the normal mode.

FIG. 8 shows the PWM section 121 when 0.5 is selected as the pulse width modulation coefficient in the toner save mode.
An example of the configuration will be shown. FIG. 8 shows a case where the image data of each color is composed of 6 bits. The latch 121a receives the 6-bit image data as it is,
It is transmitted to one 6-bit input of the data selector 121c. On the other hand, the latch 121b removes the lower 2 bits of the image data except the least significant bit (LSB) of the 6-bit image data.
The bit-most significant bit (MSB) is received as the least significant bit-higher second bit of the input, and the most significant bit of the input is connected to GND. With such a connection, the latch 121a outputs normal 6-bit image data, and the latch 121b outputs 50% of the 6-bit image data.

Therefore, the data selector 121c receiving the mode designation signal from the engine CPU 111 selects the latch 121a and the latch 121b to select the pulse width modulation coefficients 1.0 and 0.5. To do. In this case, the state in the toner save mode is to give a mode designating signal to the data selector 121c so as to select the latch 121b side.

Then, the PWM signal is generated by the PWM selector 121e selecting the pulse of arbitrary width generated by the delay line 121d by delaying the dot clock by the 6-bit image data.

The pulse width coefficient here is 0.5.
Although a circuit for realizing the above is illustrated, various changes can be made to the value of the coefficient and the circuit configuration. As described above,
The pulse width modulation coefficient of the PWM unit 121 is determined so that the desired toner adhesion amount is obtained in the toner save mode.

Here, regarding the relationship between the PWM and the density in FIG. 7, when the characteristics are different for each color (YMCK), the toner adhesion amount that does not change the color tone in color printing is determined for each color, and It is preferable to determine the pulse width modulation coefficient for each color.

When the preparation of each section is completed and the print data is sent from the host 1, printing is executed according to the instructions from the controller 101 and the engine CPU 111 (S7 to S8 in FIG. 6).

Here, after the transfer sheet is ejected, the engine CPU 111 sets the pulse width modulation coefficient of the PWM section 121 to the normal value (1.0) (S9 in FIG. 6). In the case of FIG. 8, a mode designation signal is given to the data selector 121c so that the latch 121a side is selected.

Even when the print operation is canceled by the operation panel of the operation display unit 102 or the host 1 before the start of printing (S6 in FIG. 6), the engine CPU 111 sends a mode designation signal to the PWM unit 121 in preparation for the next print. To set the pulse width modulation coefficient to a normal value (S9 in FIG. 6).

If a jam (JAM) occurs during printing (S10 in FIG. 6), the print operation (toner save mode operation) can be performed by instructing online / print again after removing the jammed paper. To be executed. That is, the mode state is maintained until the printing operation is properly completed.

By the operation of changing the pulse width modulation coefficient of the PWM section 121 in accordance with the instruction of the toner save mode as described above, when the toner save mode is selected, it is possible to realize a light print in which the toner adhesion amount is suppressed. . Further, unlike the monochrome edge-only print, since the color print is performed with the toner of the light color as a whole, the layout and the color arrangement of the print can be confirmed. Further, by setting the pulse width modulation coefficient of the PWM unit 121 independently for each color so that the color tone does not change, it is possible to confirm the color tone even in the toner save mode. Further, since the state of the toner save mode is maintained until the transfer paper is completely discharged, the toner save mode can be continuously printed even when reprinting is performed in the case of a transfer paper jam or the like. The toner usage amount can be suppressed by executing the toner save mode for at least one color instead of for all the colors.

By the way, the sensitivity characteristics of the photosensitive drum 141 may change depending on environmental conditions (temperature, humidity).
For example, as shown in FIG. 9, at the time of LL (low temperature, low humidity),
The absolute value of the electric potential of the photoconductor drum 141 does not sufficiently decrease as compared with the time of NN (normal temperature, normal humidity) and HH (high temperature, high humidity). Therefore, the intermediate color data becomes unstable.

Therefore, at the time of LL, the engine CPU 11
In response to an instruction from the No. 1, the current value of the laser diode 122 is increased to increase the laser power,
The absolute value of the surface potential of 1 is lowered so as to match the time of NN or HH. As a result, stable intermediate color data can be reproduced without being affected by environmental conditions.

As described above, by controlling the pulse width modulation coefficient in the toner save mode while controlling the laser power, the toner save mode can be stably realized even when the environmental conditions change. it can.

<Structure> FIG. 10 is a functional block diagram showing a schematic structure of a main part of the electrophotographic recording apparatus of the third structure example of the embodiment of the present invention.

In FIG. 10, the host 1 is the PDL.
It is a computer that sends various images to the electrophotographic recording apparatus 100 using (page description language) or the like. The electrophotographic recording apparatus 100 is a printer that receives image information from the host 1 and forms an image on a transfer sheet with a plurality of recording colors.

The controller 101 receives an instruction signal and image information from the host 1 and an instruction signal from the operation display unit 102, and develops a bitmap (RG described in PDL or the like).
From the image information of B, the recording color for each page (YMC or YMC
(K) processing for generating image data of bitmap) and various control units. The operation display unit 102 constitutes an operation panel that receives an operation and a display unit that performs a display in the electrophotographic recording apparatus 100, and exchanges data and commands with the controller 101.

The bitmap developing memory 103 stores the recording colors (YM
This is a memory for storing page-by-page image data for each C or YMCK). The selector 104 is means for selectively passing the image data that has undergone bitmap expansion for each recording color and performing secondary color correction.

The pattern memory 107 is a holding means for storing a later-described specific pattern for the toner save mode. The logic circuit 108 is a logic operation unit that performs a logic operation on the image data and the specific pattern to generate image data for the toner save mode. The selector 109 is a switching unit that selectively passes either image data for toner save mode or normal image data.

The engine CPU 111 is a CPU for controlling the printer engine section of the electrophotographic recording apparatus. PW
The M section 121 is means for pulse-width modulating the image data that has passed through the selector 109 to generate an image signal for driving a laser diode. The laser diode 122 is an image writing unit that emits a laser beam according to an image signal. The developing unit 131 is a unit that develops the electrostatic latent image on the photosensitive drum into a toner image, and the rotation speed of the developing sleeve is controlled by an instruction from the engine CPU 111. The photoconductor drum 141 is an image carrier on which an electrostatic latent image is generated by writing the laser diode 122.

<Operation> Here, the fourth embodiment will be described with reference to the flowchart of FIG.

Operation of host 1 or operation display unit 102
When the toner save mode is designated by (S1 in FIG. 11), the controller 101 receiving this designation sends an instruction signal corresponding to the mode designation to the engine CPU 111.
(FIG. 11S2). When the toner save mode is designated by the operation of the host 1, the host 1 notifies the controller 101 as predetermined data or command.

When the engine CPU 111 receives the mode designation instruction signal, it switches the selector 109 to the logic circuit 108 side for the toner save mode (S3 in FIG. 11). Then, when the preparation of each unit is completed and print data is sent from the host 1, printing is executed according to an instruction from the controller 101 and the engine CPU 111 (FIGS. 11 S4 to S6).

Here, in accordance with an instruction from the engine CPU 111, a specific pattern corresponding to the mode designation is read from the pattern memory 107, the logic circuit 108 executes a logical operation on the data of the specific pattern and the image data, and the result of the logical operation is calculated. Printing is executed with image data.

Various patterns are conceivable as the specific pattern. For example, as the 8 × 8 dot pattern, a pattern as shown in FIG. 12 is conceivable. In FIG. 12, the minimum value 0 and the maximum value FF form a halftone dot pattern. Then, by performing a logical product of the 8-bit image data and the specific pattern position data of FIG. 12, halftone dot meshing is realized. Further, in the case of a straight line pattern instead of halftone dots, the one as shown in FIG. 13 can be considered.

Here, it is preferable that the size of the portion where the dots are printed in the pattern is at least 2 dots × 2 dots / 1 pixel or more. 2 consecutive in this way
By setting the number of pixels or more, it is possible to check the overlapping secondary colors due to the dot shift (shift between color planes) that exists at the time of color image formation.

Further, as the specific pattern, in addition to FIG. 12 and FIG. 13, it is possible to use diagonal halftone dots, horizontal straight lines, diagonal lines, and the like. In addition, in the case of performing the above-described color check, when the toner of four colors of YMCK is used, it is necessary to use the same specific pattern for at least three colors of YMC which are chromatic colors.

Here, as the pattern memory 107,
For example, a configuration as shown in FIG. 14 can be considered. In the example shown here, a counter 107a that receives a dot clock as data for specifying a column and a counter 107b that receives L-Sync as data for specifying a row generate a total of 6-bit addresses, and an 8 × 8 pattern is generated from the ROM 107c. It is configured to read out 8-bit data for use.

Then, in the logic circuit 108, a logical operation (logical product or the like) is performed on the input image data and the pattern data to generate output image data. In the configuration illustrated in FIG. 15, regarding the input image data and the pattern data,
The logical gates 108Ga to 108Gh perform a logical product for each bit, and the logical operation result is output to the inverters 108Ba to 108Ba.
It is configured to output via 108 Bh.

By performing a logical operation using the above-described specific pattern with such a configuration, image data with halftone dots or the like applied according to the specific pattern is generated, and when the image data is printed, the toner amount is suppressed. be able to.

Here, after the transfer paper is ejected, the engine CPU 111 sets the selector 109 to the normal side (logic circuit 1
08 side (side not passing through 08) (FIG. 11 S8).
Even when the printing operation is canceled by the operation panel of the operation display unit 102 or the host 1 before the start of printing (S5 in FIG. 11), the engine CPU 111 sets the selector 109 to the normal side (the logic circuit 108 is set) in preparation for the next printing. Set to the side that does not go through (Fig. 1)
1S8).

When a jam (JAM) occurs during printing (S9 in FIG. 11), the print operation (operation in the toner save mode) is performed by instructing online / print again after removing the jammed paper. To be executed. That is, the mode state is maintained until the printing operation is properly completed.

When the toner save mode is selected by performing the logical operation of the specific pattern and the image data according to the instruction of the toner save mode as described above,
It is possible to realize a light print in which the toner adhesion amount is suppressed. Further, unlike the monochrome edge-only print, since the color print is performed with the toner of the light color as a whole, the layout and the color arrangement of the print can be confirmed. Further, by performing the logical operation of the same pattern with at least the chromatic color YMC, it is possible to confirm the color even in the toner save mode. Further, since the state of the toner save mode is maintained until the transfer paper is completely discharged, the toner save mode can be continuously printed even when reprinting is performed in the case of a transfer paper jam or the like. Note that not all colors, but at least 1
The toner usage amount can also be suppressed by executing the toner save mode for each color.

As described above in detail, when the toner save mode is executed so as to reduce the toner adhesion amount for at least one of the plurality of recording colors, the control of the rotation speed of the developing sleeve The control of the PWM modulation Basically, there are three types of control by logical operation, and control by a combination of these is also possible.

Regarding the execution of the toner save mode and the return to the normal mode, the following operation can be considered. Executing the toner save mode by receiving an instruction signal from the operation unit of the electrophotographic recording apparatus or an external device,
It is effective to ensure the operation. Continuing to execute the toner save mode until the transfer sheet is completely discharged is effective as a countermeasure against a transfer sheet jam or the like. It is effective for surely executing the toner save mode and for executing the normal mode to return from the toner save mode to the normal mode after the transfer paper on which the image is formed is completely discharged by the toner save mode. . After ejecting the transfer paper on which an image has been formed in the toner save mode, returning to the normal mode by either manual operation or automatic operation ensures execution of the toner save mode and execution of the normal mode. Is effective for. After discharging the transfer paper on which the image is formed by the toner save mode, returning to the normal mode according to the selected one of the manual operation and the automatic operation ensures that the toner save mode is executed. Useful for running in normal mode.

[0107]

As described above in detail, in an electrophotographic recording apparatus for forming an image with toner of a plurality of recording colors, a control capable of executing a toner save mode for reducing the toner adhesion amount of at least one color. According to the invention of the electrophotographic recording apparatus including the section, it is possible to reduce the toner adhesion amount for at least one of the plurality of recording colors.

Further, by controlling the rotation speed of the developing sleeve to change from the normal value in the toner save mode, it becomes possible to stably reduce the toner adhesion amount. Further, the operation can be easily performed by receiving the instruction signal from the operation unit of the electrophotographic recording apparatus or the external device and executing the toner save mode. Further, by continuously executing the toner save mode until the transfer sheet is completely discharged, it is effective as a countermeasure against the transfer sheet jam or the like. Also, it is effective for surely executing the toner save mode and for executing the normal mode to return from the toner save mode to the normal mode after the discharge of the transfer paper on which the image is formed by the toner save mode is completed. Is.

Further, according to the invention of the electrophotographic recording apparatus in which the pulse width modulation of the image signal for driving the laser diode is independently performed for each recording color in the toner save mode, at least one of the plurality of recording colors is used. The pulse width modulation of the image signal makes it possible to reduce the toner adhesion amount.

When the pulse width modulation of the image signal is independently performed for each recording color in the toner save mode, the pulse width is made shorter than in the normal mode, so that stable pulse width modulation can be performed. Further, in the toner save mode, the color-corrected image signal is subjected to pulse width modulation independently for each recording color, so that stable color image formation can be performed. In the toner save mode, the laser power is controlled according to the environmental conditions, and the pulse width is independently modulated for each recording color in the image signal with the controlled laser power as a reference, so that the environmental conditions are not affected. It is possible to form a stable color image.

Further, in an electrophotographic recording apparatus for forming an image with toner of a plurality of recording colors, an image signal for driving a laser diode is obtained from a logical operation result obtained by performing a logical operation on image data and a specific pattern. According to the invention of the electrophotographic recording apparatus provided with the logical operation means for generating at least one color, the number of pixels to be recorded for at least one of the plurality of recording colors based on the logical operation result of the image signal and the specific pattern. It is possible to effectively reduce the toner adhesion amount.

When at least yellow, magenta, and cyan chromatic colors are used as a plurality of recording colors, the same pattern is used as the specific pattern of these chromatic colors to confirm the color shift of overlapping colors. It becomes possible to do. Further, a stable operation can be realized by providing a switching unit that switches between the logical operation result and the image signal that is not logically operated, and performing switching as necessary. A more reliable operation can be realized by providing a switching unit that switches between the logical operation result and the image signal that is not logically operated based on an instruction signal from the outside, and performing switching according to the instruction signal from the outside. Further, a reliable operation can be realized by providing a switching unit for switching between the logical operation result and the image signal that is not logically operated based on the instruction signal from the operation unit, and performing the switching according to the instruction signal from the operation unit. .

Further, as the above-mentioned logical operation means, by generating the image signal for driving the laser diode from the logical operation result obtained by performing the logical operation of the image data and the specific pattern by the logical product of each bit, Stable logic operation can be executed. In addition, as the above-mentioned logical operation means, logical operation is performed on image data by extracting two or more consecutive pixels and performing logical operation, and an image signal for driving a laser diode is generated from the result of the logical operation to generate a color of a recording color. You will be able to confirm the deviation.

Furthermore, at least one of the plurality of recording colors
When the toner save mode is executed to reduce the toner adhesion amount for each color, the toner adhesion amount can be controlled by three combinations of control of the developing sleeve rotation speed, PWM modulation control, and logical operation control. Can be reduced.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a configuration of an electrophotographic recording apparatus according to an example of an embodiment of the present invention.

FIG. 2 is a flowchart showing an operating state in an example of the embodiment of the present invention.

FIG. 3 is a characteristic diagram showing a relationship between a peripheral speed ratio and a toner adhesion amount in an example of an embodiment of the present invention.

FIG. 4 is a flowchart showing an operating state in an example of the embodiment of the present invention.

FIG. 5 is a functional block diagram showing a configuration of an electrophotographic recording apparatus according to an example of an embodiment of the present invention.

FIG. 6 is a flowchart showing an operating state in an example of the embodiment of the present invention.

FIG. 7 is a characteristic diagram showing the relationship between the modulation degree and the density in the example of the embodiment of the present invention.

FIG. 8 is a block diagram showing a configuration of a PWM unit used in the electrophotographic recording apparatus according to the exemplary embodiment of the present invention.

FIG. 9 is a characteristic diagram showing the relationship between the laser power and the photosensitive drum surface potential in the example of the embodiment of the present invention.

FIG. 10 is a functional block diagram showing a configuration of an electrophotographic recording apparatus according to an example of an embodiment of the present invention.

FIG. 11 is a flowchart showing an operating state in an example of the embodiment of the present invention.

FIG. 12 is an explanatory diagram showing an example of a specific pattern for logical operation used in the electrophotographic recording apparatus according to the embodiment of the present invention.

FIG. 13 is an explanatory diagram showing another example of a specific pattern for logical operation used in the electrophotographic recording apparatus according to the example of the embodiment of the present invention.

FIG. 14 is a block diagram showing a configuration of a pattern memory used in the electrophotographic recording apparatus according to the exemplary embodiment of the present invention.

FIG. 15 is a block diagram showing a configuration of a logic circuit used in the electrophotographic recording apparatus according to the exemplary embodiment of the present invention.

[Explanation of symbols]

 1 Host 100 Electrophotographic Recording Device 101 Controller 102 Operation Display Unit 103 Bitmap Development Memory 104 Selector 111 Engine CPU 121 PWM Unit 122 Laser Diode 131 Developing Unit 141 Photoreceptor Drum

Claims (21)

[Claims] 1. An electrophotographic recording apparatus for forming an image with toner of a plurality of recording colors, comprising a control unit capable of executing a toner save mode for reducing the amount of toner adhering to at least one color. Electrophotographic recording device. 2. The electrophotographic recording apparatus according to claim 1, wherein the control unit reduces the toner adhesion amount by controlling the rotation speed of the developing sleeve in the toner save mode. 3. The control unit controls the modulation factor when pulse-width-modulating the image signal for driving the writing unit independently for each recording color in the toner save mode. The described electrophotographic recording device. 4. An electrophotographic recording apparatus for forming an image with toner of a plurality of recording colors, wherein an image signal for driving a writing means is obtained from a logical operation result obtained by performing a logical operation on image data and a specific pattern. An electrophotographic recording apparatus, comprising: a logical operation unit that generates at least one color; and a control unit that causes the logical operation unit to execute a toner save mode for reducing a toner adhesion amount of at least one color. . 5. An electrophotographic recording apparatus for forming an image with toners of a plurality of recording colors, comprising a control section capable of executing a toner save mode for reducing the amount of adhering toner of at least one color, wherein the control section is In the toner save mode, the toner adhesion amount is controlled by controlling the number of rotations of the developing sleeve and controlling the modulation degree when the pulse width of the image signal for driving the writing unit is independently modulated for each recording color. An electrophotographic recording apparatus, characterized in that 6. An electrophotographic recording apparatus for forming an image with toner of a plurality of recording colors, a control section capable of executing a toner save mode for reducing the amount of toner adhering to at least one color, image data and a specific pattern. And a logical operation unit that generates an image signal for driving the writing unit for at least one color from a logical operation result obtained by performing a logical operation with the control unit, and the control unit is configured to rotate the developing sleeve in the toner save mode. And controlling the logical operation of the logical operation means so as to reduce the toner adhesion amount of at least one color. 7. An electrophotographic recording apparatus for forming an image with toner of a plurality of recording colors, a control section capable of executing a toner save mode for reducing a toner adhesion amount of at least one color, image data and a specific pattern. And a logical operation means for generating an image signal for driving the writing means for at least one color from a logical operation result obtained by performing the logical operation with the control section for each recording color in the toner save mode. By independently controlling the degree of modulation when the pulse width modulation of the image signal for driving the writing unit and controlling the logical operation of the logical operation unit, the toner adhesion amount of at least one color is reduced. An electrophotographic recording device characterized by being controlled. 8. The control unit sets a duty ratio smaller than that in a normal mode when the pulse width modulation of the image signal is independently performed for each recording color in the toner save mode. The electrophotographic recording device according to claim 5 or 7. 9. The control unit controls a modulation factor in independently performing pulse width modulation for each recording color on the image signal after color correction in the toner save mode. The electrophotographic recording apparatus according to claim 3, claim 5, or claim 7. 10. In the toner save mode, the control unit controls the power of the writing unit according to environmental conditions, and the pulse width is independently set for each recording color in the image signal with reference to the controlled power of the writing unit. 8. The electrophotographic recording apparatus according to claim 3, wherein the degree of modulation at the time of modulation is controlled. 11. An electrophotographic recording apparatus, wherein at least yellow, magenta, and cyan are used as the plurality of recording colors, and an image is formed by toners of these colors, wherein the logical operation means includes yellow, magenta, and cyan. The electrophotographic recording apparatus according to claim 4, wherein the same pattern is provided for each color and the same pattern is used as the specific pattern for each color. 12. An electrophotographic recording apparatus for forming an image with toner of a plurality of recording colors, wherein an image signal for driving a writing means is obtained from a logical operation result obtained by performing a logical operation on image data and a specific pattern. 8. A logical operation means for generating at least one color is provided, and a switching section for switching between a logical operation result and an image signal that is not logically operated is provided. Electrophotographic recording device. 13. An electrophotographic recording apparatus for forming an image with toner of a plurality of recording colors, wherein an image signal for driving a writing means is obtained from a logical operation result obtained by performing a logical operation of image data and a specific pattern. 7. A logical operation means for generating at least one color is provided, and a switching unit is provided for switching between a logical operation result and an image signal that is not logically operated based on an instruction signal from the outside. The electrophotographic recording apparatus according to claim 7. 14. An electrophotographic recording apparatus for forming an image with toner of a plurality of recording colors, wherein an image signal for driving a writing means is obtained from a logical operation result obtained by performing a logical operation on image data and a specific pattern. 7. A logical operation means for generating at least one color is provided, and a switching section is provided for switching a logical operation result and an image signal which is not logically operated based on an instruction signal from the operation section. Alternatively, the electrophotographic recording device according to claim 7. 15. An electrophotographic recording apparatus for forming an image with toner of a plurality of recording colors, wherein writing is performed from a logical operation result obtained by performing a logical operation of image data and a specific pattern by a logical product of each bit. At least one logical operation means for generating an image signal for driving the means.
7. The method according to claim 4 or 6, wherein the color is provided.
Alternatively, the electrophotographic recording device according to claim 7. 16. An electrophotographic recording apparatus for forming an image with toner of a plurality of recording colors, wherein logical operation is performed on image data by extracting two or more consecutive pixels and performing logical operation, and writing means from the logical operation result. 8. The electrophotographic recording apparatus according to claim 4, further comprising logical operation means for generating a driving image signal for at least one color. 17. The electrophotographic recording apparatus according to claim 1, wherein the control unit executes a toner save mode in response to an instruction signal from the operation unit or the outside. 18. The electrophotographic recording apparatus according to claim 1, wherein the control unit executes the toner save mode until the transfer sheet is completely discharged. 19. The electrophotographic recording according to claim 1, wherein the control unit returns to a normal mode after the transfer paper on which the image is formed in the toner save mode is discharged. apparatus. 20. The control unit returns to the normal mode by either a manual operation or an automatic operation after the transfer sheet on which an image is formed in the toner save mode is ejected. The electrophotographic recording apparatus according to claim 16. 21. The control unit returns to the normal mode according to the selected side of either manual operation or automatic after discharging the transfer sheet on which an image is formed in the toner save mode. The electrophotographic recording apparatus according to any one of claims 1 to 16.