JPH01217479A - Image forming device - Google Patents

Abstract

PURPOSE:To surely form original images when the original images include a color whose sensitivity of an image carrier is high by inserting a 2nd filter whose color is the complementary color relation of that of 1st filters between a scanning means and a photosensitive body drum and forming images. CONSTITUTION:A control means discriminates whether the original images include the color whose sensitivity of the image carrier is high by the original images read through the 1st filters fa and fb by means of a reading means 29 and the original images read without interposing the 1st filters fa and fb. When the color is included, the 2nd filter fc whose color is the complementary color relation of that of the 1st filters fa and fb is inserted between the scanning means and the photosensitive body drum so as to form images. Thus, even when the original images include the color whose sensitivity of the image carrier is high, the original images can surely be formed without performing any special operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an image forming apparatus capable of determining, for example, the color of an original image.

(Prior Art) As is well known, photosensitive drums used in electronic copying machines have different sensitivity to the color of light depending on the material of the photosensitive drum. For example, selenium Se is highly sensitive to blue-based light.

By the way, when the photosensitive drum is made of selenium, if there is a blue part in the original image, it becomes difficult to copy the image of this blue part. .

(Problems to be Solved by the Invention) Conventionally, in such cases, the operator has made copies by darkening the exposure settings or interposing a yellow transparent sheet between the document table and the document. However, it is troublesome to perform such an operation every time the original contains blue.

This invention solves the problem of the complexity of operations when copying originals containing colors to which the photoreceptor drum is highly sensitive. It is an object of the present invention to provide an image forming apparatus that can reliably form images without performing any manual operations.

[Structure of the Invention (Means for Solving the Problems) This invention provides a scanning means for exposing and scanning an original image, an image carrier on which an optical image guided by the scanning means is formed, and an image carrier on the image carrier. An image forming apparatus comprising a developing means for developing a formed optical image, a transfer means for transferring the developed image onto a transfer material, and a fixing means for fixing the transferred image on the transfer material. , a reading means for reading one optical image guided by the scanning means, and a first filter that can be interposed between the reading means and the scanning means and matched with a wavelength to which the image carrier is sensitive. a second filter that can be interposed between the scanning means and the image carrier and has a complementary color relationship with the first filter; If it is determined that a color with high sensitivity is included,
It is comprised of a control means for inserting the second filter between a scanning means and an image carrier.

(Function) The present invention provides image bearing in the document image by the control means based on the document image read by the reading device through the first filter and the document image read without the first filter. It is determined whether or not a color to which the human body is highly sensitive is included, and if so, a second filter having a complementary color relationship with the first filter is inserted between the scanning means and the photosensitive drum. By forming the image, even if the original image includes a color to which the image carrier is sensitive, the original image can be reliably formed without any special operation.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 schematically shows an image forming apparatus of the present invention, such as a copying machine. That is, a document table (transparent glass) 2 for supporting a document is fixed to the upper surface of the copying machine main body 1. This document table 2 has a fixed scale 2 which serves as a reference for setting the document. Further, a document cover 1 that can be opened and closed is provided near the document table 2.

The document placed on the document table 2 is exposed and scanned by an optical system consisting of an exposure lamp 4 and mirrors 5, 6, and 7 moving back and forth along the lower surface of the document table 2. . In this case, mirror 6.7 moves at half the speed of mirror 5 so as to maintain the optical path length. The light reflected from the original by the scanning of the optical system, that is, the light reflected from the original by the light irradiation of the exposure lamp 4, is reflected by the mirror 5, 6, 7, passes through the variable magnification lens block 8, and further passes through the mirror 91. .92, 93 and is guided to the photosensitive drum 1o, so that an image of the document is formed on the surface of the photosensitive drum 10.

The photosensitive drum 10 rotates in the direction of the arrow a in the figure, and the surface is first charged by the charging device 11, and then the image is exposed to slit light in the exposure section ph, so that an electrostatic latent image is formed on the surface. Ru. This electrostatic latent image is made into a visible image by being deposited by developing devices 121 and 122, each of which contains, for example, red or black toner and is selectively operated as required.

On the other hand, the paper (transfer material) is delivered from the selected upper paper feed cassette 131 or lower paper feed cassette 132 to the feed rollers 141 and 142 and the roller pair 15. ．． The sheets are taken out one by one by the sheet guide path 16. ．． 162, and is guided to a pair of registration rollers 17, and guided to a transfer section by this pair of registration rollers 17.

Further, the upper paper feed cassette 131 is provided with a guide 13a for manual paper feed, and the paper guided and fed by this guide 13a for manual paper feed is transferred to the feed roller 14a, 15], is guided to a pair of registration rollers 17 via a paper guide path 161, and guided to a transfer section by this pair of registration rollers 17. Here, the paper feed cassettes 131 and 132 are removably provided at the lower right end of the main body 1, and either one can be selected on the operation panel described later. The cassette size of each of the paper feed cassettes 131 and 132 is detected by cassette size detection switches 601 and 602, respectively. These cassette size detection switches 60, . Reference numeral 602 is composed of a plurality of microswitches that are turned on and off in accordance with the insertion of cassettes of different sizes.

The paper sent to the transfer section comes into close contact with the surface of the photoreceptor drum 10 at the transfer charger 18, so that the toner image on the photoreceptor drum 10 is transferred by the action of the charger 18. The transferred paper is electrostatically peeled off from the photoreceptor drum 10 by the action of a peeling charger 19, conveyed by a conveyor belt 20, and sent to a fixing roller 21 as a fixing device provided at the end of the conveyor belt 20. The transferred image is fixed by passing through this area. The sheet after fixing is then discharged to a tray 23 outside the main body 1 by a pair of delivery rollers 22.

Further, residual toner on the surface of the photoreceptor drum 10 after transfer is removed by a cleaner 24, and a static elimination lamp 2
5, the afterimage is erased to return to the initial state.

Incidentally, 26 is a cooling fan for preventing the temperature inside the main body 1 from rising.

Further, the exposure lamp 4 and the mirror 5 are connected to the first carriage 2.
8a, the mirror 6.7 is provided on the second carriage 2
8b. When the copying machine main body 1 is in a standby state, the first carriage 28a is located at a position indicating the copying range of the original defined by the currently selected paper size and copying magnification, for example, as shown in FIG. It is on standby at the standby position RP indicated by .

On the other hand, a document image reading device 29 is provided on the side of the variable magnification lens block 8, and the mirrors 92, 93
A color correction device 27 is provided between each other so that it can be inserted into and removed from the optical path.

2 and 3 show the reading device 29. FIG. The lens 29a includes the exposure lamp 4 and the mirror 5.6.
．． The original image guided by CCD line sensor 2
This leads to 9b. A rotator 29c is provided at the entrance portion of the lens 29a. A rotary solenoid 29d is provided at one end of the rotating element 29c, and the rotating element 29c is rotated in the direction of the arrow shown in FIG. 3 by the rotary solenoid 29d. Further, at the other end of the rotating element 29c, a filter fa made of red and fb made of blue are provided, for example.

fb is the lens 2 when the rotator 29c is rotated.
It is designed to be selectively inserted into the optical path of 9a.

The photosensitive drum 10 uses the blue filter fb.
This is because it is made of selenium Se, which has high sensitivity to blue light.

FIG. 4 shows the color correction device 27. As shown in FIG. A yellow complementary color filter fc having a complementary color relationship with the blue filter fb provided in the reading device 29 is provided on the frame 27a. A plunger 27c of a solenoid 27b is provided at one end of the frame 27a, and when the solenoid 27b is driven, the frame 27a is moved in the direction of the arrow in the figure, and the filter fc is inserted into and removed from the optical path. It has become so.

FIG. 5 shows an operation panel 30 provided on the main body 1. 301 is a copy key for commanding the start of copying, 30□
303 is a display section that displays the operating status of each section and paper jams, etc.; 304 is a cassette selection key that selects upper and lower paper feed cassettes 1B, 1B□; -1305 is a selection key; 306 is a magnification setting key for setting the enlargement/reduction magnification of copying in a predetermined relationship; 307 is a zoom key for steplessly setting the enlargement/reduction magnification; and 308 is a zoom key for setting the set magnification. A display section 309 displays a density setting section for setting the copy density, 30a a red designation key for specifying the developing device 121 containing, for example, red toner, and 30b indicating the developing device 122 containing, for example, black toner. This is the black designation key.

FIG. 6 shows the configuration of the main parts of the control system.

The control section 41 performs overall control of the copying machine main body 1, and for example, controls J, 1% by a microcomputer.
has been completed. This control section 41 includes the operation panel 3
0, an A/D conversion circuit 42 that converts the output signal of the CCD line sensor 29b constituting the reading device 29 into a digital signal, a solenoid drive circuit 43 that drives the rotary solenoid 29d, and the first and second carriages 28a128b. a motor drive circuit 45 that controls the drive of the motor 44 that drives the exposure lamp 4, a lamp regulator 46 that controls the lighting of the exposure lamp 4, and the A/D conversion circuit 42.
The first and second memories 47 and 48 store the conversion output of
, and a solenoid drive circuit 49 that drives the solenoid 27b of the color correction device 27.

The operation of the above configuration will be described with reference to FIGS. 7 and 8.

As shown in FIG. 8(a), it is assumed that the original OG contains an image E consisting of a blue color, for which the sensitivity of the photoreceptor drum 10 is high. When this original is placed on the original table 2 and the copy key 301 of the operation panel 30 is operated, the control unit 4
1, the operation shown in FIG. 7 is performed.

That is, the rotary solenoid 29d is driven by the solenoid drive circuit 43, and the red filter fa of the rotator 29c is inserted into the optical path of the lens 29a (step 5TI). In this state, the lamp regulator 46
The exposure lamp 4 is turned on, and the motor 44 is driven by the motor drive circuit 45, and the first carriage 28a is moved from the standby position shown in FIG. 1 toward the fixed scale 21 to expose and scan the original ( Step 5T2).

At this time, devices related to the developing process, such as the photosensitive drum 10 and the charging device 11, are stopped.

Along with this exposure scanning, the light from the document guided by the mirrors 5 to 7 passes through the red filter fa.

The light enters the CCD line sensor 29b through the lens 29a and is read by the CCD line sensor 29b (step 5T3). This CCD line sensor 29b
The output signal is converted into a digital signal by the A/D conversion circuit 42, and the signal corresponding to the digitized original image is stored in the first memory 4 as shown in FIG. 8(b).
7 (step 5T4). In this way,
When the reading of the original image using the red filter fa is completed (step 5T5), the exposure lamp 4 is turned off,
Standby position RP where the first carriage 28a indicates the copying range
(Step 5T6).

Next, the rotary solenoid 29d is driven by the solenoid drive circuit 43, and the blue filter fb of the rotator 29c is inserted into the optical path of the lens 29a (step 5T7). In this state, the lamp regulator 46
The exposure lamp 4 is turned on, and the motor 44 is driven by the motor drive circuit 45, and the first carriage 28a is moved from the standby position RP shown in FIG. 1 in the direction of the fixed scale 21, and the original is exposed and scanned. (Step 5T8).

At this time, devices related to the developing process, such as the photosensitive drum 10 and the charging device 11, are also stopped.

Along with this exposure scanning, the light from the original guided by the mirrors 5 to 7 passes through the blue filter fb.

The light enters the CCD line sensor 29b through the lens 29a and is read by the CCD line sensor 29b (step 5T9). This CCD line sensor 29b
The output signal is converted into a digital signal by the A/D conversion circuit 42, and the signal corresponding to the digitized original image is stored in the second memory 4 as shown in FIG. 8(c).
8 (step 5TIO). In this way, when the reading of the original image using the blue filter fb is completed (step 5T11), the exposure lamp 4 is turned off and the first carriage 28a is stopped at the position of the fixed scale 21 (step 5T12). .

In this state, it is determined from the signals corresponding to the original image stored in the first and second memories 47 and 48 whether or not the original image contains blue-based colors. That is,
First, the signals stored in the second memory 48 are shown in FIG.
) is reversed as shown. Next, this inverted signal is logically ANDed with the signal stored in the first memory 47 shown in FIG. 4(b). If there is a blue-colored image, only that part becomes a high-level signal, as shown in FIG. 4(e). Therefore, by determining whether this high-level signal is appropriate or not, it is possible to determine whether or not there is a blue-based image in the original image (step 5T13.14).

As a result, if it is determined that the original has a blue image, the solenoid drive circuit 49 causes the solenoid 2 to
7b is driven, and the complementary color filter fc is inserted into the optical path (step 5T15).

Thereafter, the original is exposed and scanned by normal operation, and an original image is formed on the paper (step 5T16).

If it is determined that the document does not contain a blue image, a normal image forming operation is performed with the complementary color filter fc taken out of the optical path.

According to the two-legged embodiment, the reading device 29 reads a document image prior to image formation on the document, and determines whether or not the read document image contains a color to which the photoreceptor drum 10 is highly sensitive. If it is included, a complementary color filter fc is inserted into the optical path and an image forming operation is performed. Therefore, even if the original image includes a color to which the photoreceptor drum 10 is highly sensitive, it is possible to reliably form the original image.

Moreover, the operator can use the copy key 30. It is easy to operate since no special operations are required except for operating the .

Incidentally, in the above embodiment, the document image is read using red and blue filters, but the invention is not limited to this. For example, only a blue filter is provided, and first, the document image is read without any intervening filter. It is also possible to obtain the same effect as in the above embodiment by reading the original image (elephant) and then reading the original image through a blue filter.

Further, the filters fb and fc are not limited to blue and yellow, but may be changed depending on the material of the photoreceptor drum.

Furthermore, in the above embodiment, the first filter is inserted into and removed from the optical path to read the original image, and if the original image contains a color to which the photoreceptor drum is sensitive, the second filter is inserted. Although the present invention is described above, the present invention is not limited to this, and the same effect can be obtained by, for example, switching the exposure color of the original image.

That is, first, the original image is read when the original image is irradiated with light to which the photoreceptor drum has high sensitivity, and when the original image is irradiated with light to which the photoreceptor drum has low sensitivity, and from these, the color to which the photoreceptor drum is more sensitive is detected in the original image. If the original image is exposed and scanned by irradiating the original with light of a color to which the photoreceptor drum has low sensitivity, it is possible to reliably form an original image.

It goes without saying that various other modifications can be made without departing from the gist of the invention.

[Effects of the Invention] As described in detail above, according to the present invention, the original image read by the reading means through the first filter,
The control means determines whether or not the document image contains a color to which the image carrier is highly sensitive, and if the color is included, the scanning means By inserting a second filter having a complementary color relationship to the first filter between the photosensitive drum and the photosensitive drum to form an image, even if the original image contains a color to which the image carrier is sensitive, no special without performing any operations.
An image forming apparatus that can reliably form a document image can be provided.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing an embodiment of an image forming apparatus according to the present invention, FIGS. 2 and 3 each show the configuration of a reading device, and FIG. 2 shows an extracted main part. A top view, FIG. 3 is a perspective view showing the main parts, FIG. 4 shows the configuration of the color correction device, a perspective view showing the main parts, and FIG. 5 shows the structure of the operation panel. The plan view and FIG. 6 are configuration diagrams showing the main parts of the control system, and FIGS. 7 and 8 are diagrams shown for explaining the operation, respectively. DESCRIPTION OF SYMBOLS 1... Copying machine main body, 2... Document table, 4... Exposure lamp, 10... Photosensitive drum, 27... Color correction device, 28a, 28b... 11th second carriage, 29・
...reading device, 29a...lens, 29b...C
CD line sensor, fa, fb...filter, fc...
...Complementary color filter, 41...control unit. Applicant's representative Patent attorney Takehiko Suzue Figure 3 Figure 6 Figure 7 (a) Section 80 (C) M8 (d'') (e)
Figure 8

Claims (1)

[Scope of Claims] A scanning means for exposing and scanning an original image, an image carrier on which an optical image guided by the scanning means is formed, and a developing means for developing the optical image formed on the image carrier. In an image forming apparatus comprising a transfer means for transferring the developed image onto a transfer material, and a fixing means for fixing the image transferred onto the transfer material, an optical image guided by the scanning means is read. a first filter that can be interposed between the reading means and the scanning means and matched to a wavelength to which the image carrier is sensitive; a second filter that can be interposed and has a complementary color relationship with the first filter; and a second filter that is determined from the output of the reading means that the original image contains a color to which the image carrier is highly sensitive. In this case, the second
An image forming apparatus comprising: a control means for inserting a filter between a scanning means and an image carrier.