JP3110748B2 - Image processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image processing apparatus.

[Prior Art] In the editing of publications such as newspapers and magazines, it is sometimes convenient to gradually reproduce the posted color images from the key, red, eye, and ski editions used for printing. There are many. For example, when a full-color copying machine is used for such processing, the following operation has conventionally been performed. That is, every time the developing process is performed with the magenta, cyan, yellow, and black toners, the red, yellow, yellow, and black plates are sequentially set on the platen at a predetermined timing, and the document of each plate is sequentially read.

[Problems to be Solved by the Invention] However, in the above conventional example, the image quality of the reproduced image has not been sufficiently considered. Images for printing may be of various resolutions. When the above-described gradual image is used, for example, for confirming the finished state of a printed matter, it is preferable to reproduce the image as an image having various resolutions like a printed image.

The present invention has been made in view of the above circumstances, and has as its object to provide an image processing apparatus in which a suitable correction process corresponding to various resolutions is realized in each of a normal print mode and a plate inspection mode, and the apparatus scale is reduced. .

[Means for Solving the Problems] In order to solve this problem, an image processing apparatus according to the present invention uses a correction unit that performs a correction process on a color image signal of a plurality of components, and uses the corrected color image signal. An image processing apparatus having printing means for performing full-color printing by using an instruction means for switching between a normal print mode and a plate inspection mode, and a normal print mode provided for each resolution when the normal print mode is instructed. Data for correction processing is selectively set from the data for correction processing for the mode in the correction means, and when the inspection mode is instructed, the data for correction processing for the inspection mode provided for each resolution is provided. Control means for selectively setting correction processing data in the correction means.

[Operation] In this configuration, when the normal print mode is instructed, the correction processing data is selectively set in the correction unit from the correction processing data for the normal print mode provided for each resolution, and the correction is performed. When the plate mode is instructed, the correction processing data is selectively set in the correction means from the correction processing data for the plate inspection mode provided for each resolution, and an image is formed according to the set correction characteristics. Since the correction is performed on the data, in each of the normal print mode and the plate inspection mode, a suitable correction process corresponding to various resolutions can be realized, and the apparatus scale can be reduced.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows the overall configuration of a copying machine according to an embodiment of the present invention. The copying machine shown in FIG. 1 is a full-color copying machine that employs an electrophotographic recording system in an image forming process. Although the overall configuration is already well known,
An outline will be described.

A transfer material holding member, that is, a transfer drum 13 is disposed at a central portion in the copying machine main body 40. The transfer drum 13 is rotatably supported in the direction of the arrow in FIG. 1 (clockwise direction). On the inner peripheral side of the transfer drum 13, a transfer material suction means, ie, a suction charger 11, a transfer charger 14, The static elimination charger 17, the separation pressing roller 23, and the transmission sensor 54 are provided. On the other hand, on the outer peripheral side of the transfer drum 13, the charge removing device 18 starts being arranged in pairs with the charge removing charger 17,
9, the separation claw 20 is paired with the separation pressing roller 23, and the sensor 55
Are arranged in pairs with the transmission sensor 54. Further, the transfer drum cleaner 34 and the transfer material suction means, that is, the contact roller 12 are paired with the suction charger 11, and the photosensitive drum 2 and the like are transferred to the transfer charger 14.
And are arranged in pairs.

The downstream end of the paper feed guide 9 having the registration roller pair 10 is in contact with the contact roller 12. In the middle of the paper feed guide 9, a pair of transmission type sensors 50 and 51 (a sensor before the register) for creating a loop amount at the registration roller 10 and for checking whether the transfer material is plain paper or OHP paper. ) Is arranged. A feed roller pair 24, a pick-up roller 25, a feed roller pair 26, and a pick-up roller 27 are provided at the upstream end of the paper feed guide 9 branched in two directions. Also a manual paper feed port for manual paper feed
60 and a manual feed length sensor 52 are arranged.

A fixing device 22 having a pressure roller 30, a fixing roller 31, an oil sponge 32, a web 33, and the like is provided in the upper right region in the copying machine main body 40 with respect to the separation claw 20. The fixing device
A transfer material conveyance belt 21 is provided between the transfer material conveyance belt 21 and the separation claw 20, and a motor 35 is provided above the transfer material conveyance belt 21.
Is installed.

In the upper area of the copying machine main body 40, a first mirror 5, a folding mirror 6, a range system 7, and a color image sensor 8 are arranged, including an original illumination lamp 4.

In the lower area of the copying machine main body 40, the photosensitive drum 2 is provided.
Developing means, that is, a horizontally movable developing device 1 is disposed in proximity to the outer peripheral surface of the developing device. Details of the horizontally movable developing device 1 will be described later. The photosensitive drum 2 is rotatably supported in the direction of the arrow (counterclockwise) in FIG. 1 and is arranged around the photosensitive drum 2 to execute an image forming sequence together with the photosensitive drum 2. Necessary devices include the above-described transfer drum 13, transfer charger 14 and horizontally movable developing device 1, a primary charger 3, a potential sensor 28, a charge eliminator 15 and a cleaning member 16, and a charge eliminator. A laser beam scanner unit 29 and the like adjacent to the electric machine 15 are provided.

The horizontal start-type developing device 1 includes a moving body 1a that moves horizontally in the horizontal direction in FIG. 1, a magenta developing device 1M, a cyan developing device 1C, a yellow developing device 1Y, and a black device mounted on the moving body 1a. And a developing device 1Bk. These developing units 1M, 1C, 1Y,
1Bk, four toner hoppers corresponding to the respective toner hoppers are arranged side by side in the surface direction of FIG. 1. Each of the toner hoppers and each of the developing devices 1M, 1C, 1Y, and 1Bk is such that the moving body 1a is Are connected by various known flexible means so that the developer can always be replenished even if the developer moves.

A case in which copying is performed in the full-color normal mode using the copying machine having the above configuration will be described below. First, the outer peripheral surface of the photosensitive drum 2 is charged substantially uniformly by the primary charger 3, and then the original (not shown) is scanned while being illuminated by the original illumination lamp 4, and the reflected light is
The image is given to the color image sensor 8 via the first mirror 5, the reflection mirror 6, and the lens system 7 to form an image. When the reflected light is color-separated in the color image sensor 8 to generate a magenta image signal, the magenta image signal modulates the laser light E emitted from the laser beam scanner unit 29. Then, image exposure is performed by the modulated laser light E, and an electrostatic latent image is formed on the outer peripheral surface of the photosensitive drum 2. This electrostatic latent image is developed by the magenta developing device 1M which is in standby at the developing position on the outer peripheral surface of the photosensitive drum 2 as shown in FIG.

On the other hand, the transfer material sent out toward the transfer drum 13 at a predetermined timing via the paper feed guide 9 and the registration roller pair 10 is electrostatically transferred by the attraction charger 11 and the contact roller 12 to the transfer drum 13. Is wound around the outer peripheral surface. Transfer drum 13
Is normally set so as to synchronize with the peripheral speed of the photosensitive drum 2, and the toner image formed on the outer peripheral surface of the photosensitive drum 2 by the magenta developing device 1M is transferred to the transfer charger 14
Is transferred to a transfer material. The transfer drum 13 keeps rotating at a constant peripheral speed, and transfers a toner image formed on the outer peripheral surface of the photosensitive drum 2 by a new color toner (cyan in FIG. 1). Prepare for.

At the same time, the photosensitive drum 2 is neutralized by the neutralizing charger 15, and the toner remaining on the photosensitive drum 2 is cleaned by the cleaning member 16.
It is charged substantially uniformly by the next charger 3 and is subjected to image exposure by a laser beam E modulated by a cyan image signal. At this time, the cyan developing device 1C stands by at a predetermined developing position as the moving body 1a moves in the direction of the arrow in FIG. The laser light E modulated by the cyan image signal
Thus, the electrostatic latent image formed on the outer peripheral surface of the photosensitive drum 2 is developed to form a cyan toner image.

The above-described steps are continuously performed on the yellow original image information and the black original image information. When the transfer of the four color toner images onto the transfer material is completed, the four images transferred onto the transfer material are transferred. Colored toner image is used for static elimination charger 1
After being neutralized at 7, 18 and recharged by the charger 19,
The transfer material is separated from the transfer drum 13 by the separation claw 20. The transfer material separated from the transfer drum 13 by the separation claw 20 is sent to the fixing device 22 by the transfer material transport belt 21 to complete a series of image forming sequences and obtain a desired full-color print image.

FIG. 2 shows a configuration diagram of a control system provided in a copying machine according to an embodiment of the present invention.

The ROM 101 contains a control program and the like, and also stores nonvolatile fixed data such as gamma correction data. RAM 102 is an external CPU 1 via I / O 103
Various data given to 00 are stored. I / O103
Is for connecting between the CPU 100 and various external devices.

A transfer drum home position sensor (hereinafter, referred to as a transfer drum HP sensor) 104 is installed so as to detect one detection target (not shown) provided on the rotating transfer drum 13. Transfer drum HP sensor 104
Processing is performed such that a predetermined pulse signal is output as a detection signal of a reference position set on the transfer drum 13 every time the detection target object passes through the detection area of the HP sensor 104 due to the rotation of the transfer drum 13. Perform

The pulse encoder 105 detects the number of rotations of the motor 35 that rotationally drives the transfer drum 13 and outputs a predetermined pulse signal. The BD signal generation circuit 106 is provided in the laser beam scanner unit 29 and outputs a horizontal synchronizing signal (that is, a BD signal).

The image processing circuit 107 is a circuit that performs image processing such as shading correction, brightness / density conversion, and zoom movement of an image signal from the color image sensor 8. Sensor before register
Reference numeral 108 denotes a transmission sensor, which is disposed immediately before the registration roller 10 and detects whether the fed transfer material is plain paper or OHP.

The manual feed length detection sensor 109 detects the length of paper fed from the manual paper feed port 60, and detects the type of OHP paper (A
The length of 4 lengths or the length of A4 width is determined by the detection of this sensor.

Further, the transfer drum sensor 114 detects whether the sheet adsorbed on the transfer drum is not peeled off, or detects whether the sheet is adsorbed at a correct position.

The developing device motor controller 110 controls the operation of the moving body 1a by the motor 111. The optical motor controller 112 controls the operation of the optical system, that is, the motor 1
The drive of the document illumination lamp 4, the first mirror 5, and the return mirror 6 is controlled by the controller 13. Further, the transfer drum HP sensor output HP determined to be necessary for document scanning by the CPU 100 is input to the optical system motor controller 112.

FIG. 3 shows an example of an operation unit of a copying apparatus to which the present invention is applied. The operation unit will be described below.

A key 301 is a group of numeric keys used to set the number of copies, and a key 302 is a clear / key for requesting clearing of the number of copies and stopping of the operation.
A stop key, a key 303 are reset keys for returning a copy mode to a standard state, a key 304 is a start key for starting a copy operation, and a key 306 is a key for adjusting a copy density. The result is displayed on a display 305.

A key 318 is a key for selecting a paper feed stage, a key 310 is a key for equalizing the copy magnification, a key 309 is a key for selecting an enlargement magnification and a reduction magnification, and a key 329 is a key for selecting and canceling the enlargement continuous shooting mode. is there.

A display unit 319 is a liquid crystal display unit using a dot matrix, and a key group 307 is a control key used to select or change the display content of the display unit 319. That is, the key 307u,
The display contents are selected by moving the index in the display unit 319 up, down, left, and right with d, l, and r, respectively, and the keys 307-o are selected.
The end of the selection is designated by k.

Keys 311 are a guide key and an LED used to display operation explanations and function explanations on the display unit 319. L
While the ED is lit, it indicates that it is in the guidance mode.

A key 313 is a preheating key used to bring the apparatus into a preheated state and to release the apparatus. A key 315 is a key for performing color selection, and the selection result is displayed on the LED 314. The key 316 is a key for the machine to automatically adjust the copy density, and the LED 317 indicates that the function is valid.

Key 323 is used to set the zoom magnification.
The setting screen is displayed on the display unit 319. A key 326 is a key for setting a horizontal / horizontal independent zoom magnification, and a setting screen at that time is displayed on the display unit 319. A key 321 is a key and an LED for copying a manuscript of 20 facing pages on separate papers.

A key 325 is a key and an LED for moving a document to the right or left to make a binding margin and copying. A setting screen is displayed on the display unit 319. A key 328 is an image create key, and is a key and an LED for setting an image create mode such as a negative / positive inversion, a bust, and the like.
Will be displayed.

Key 320 is for adjusting color balance (magenta, cyan, black, yellow) and LED
Thus, the setting screen is displayed on the display unit 319. A key 324 is a color mode selection key for selecting a color that cannot be set with the key 315. The setting screen is displayed on the display unit 319. A key 330 and a key 331 at the upper right of the operation unit are a key and an LED for entering a film projector mode and a plate inspection mode, respectively.

FIG. 4 shows a message displayed on the display unit 319 when the key 331 is pressed to enter the plate inspection mode.

Next, the control procedure of the plate inspection mode in this embodiment will be described based on the flowchart of FIG.

First, when the key 331 is pressed, a fourth
The message of ms401 in the figure is displayed (S501). When the operator places the red plate on a platen (not shown) in accordance with the displayed instruction and presses the start key 304 (S502),
The transfer material is fed (S503), is electrostatically wound around the outer peripheral surface of the transfer drum 13 (S504), and an image is formed on the surface of the transfer material using magenta toner (S505). When these processes are completed, the transfer drum 13 stops at a predetermined phase and stands by while winding the transfer material (S506), and the message ms40 is displayed.
2 is displayed (S507) and the apparatus enters a state of waiting for an instruction from the operator.

When the operator places the eye plate on the platen and presses the start key 304 in accordance with the instruction on the display (S508), an image is formed on the surface of the transfer material already wound around the transfer drum 13 using cyan toner (S509). The transfer drum 13 stops at the predetermined position again and waits (S510), and the message ms403
Is displayed (S511) to enter a state of waiting for an instruction from the operator.

The same control procedure as the image formation using the cyan toner is also performed in the image formation using the yellow toner (S512 to S515).

Finally, according to the instruction (S515) of the message ms404, the printing plate is placed on the platen and the start key 304 is pressed (S516), and an image is formed on the transfer material surface with black toner (S517). Is removed from the transfer drum 13 (S518), the toner is fixed on the transfer material, and discharged outside the copying machine main body (S519), and a series of procedures is completed.

Second Embodiment FIG. 6 is an external view when a document feeder is connected to the copying machine of the embodiment. 601 is the main body, 602 is the upper paper cassette, 603 is the lower paper cassette, 604 is the manual paper tray,
An output tray 605 and an original feeder 606 are provided.

FIG. 7 is a perspective view of the document feeder. 701 is a document feed tray capable of setting a plurality of documents, 702 is a slide tray for sliding and aligning documents according to the size of the document, 703 is an auxiliary tray for setting a document long in the feed direction, and 704 is a document feeder. A document sensor for detecting that a document is set on the paper tray 701.

The operation in the second embodiment will be described with reference to the above configuration and the time chart in FIG. First, the inspection mode key 331
Is pressed, the message ms801 shown in FIG.
Is displayed. According to the message, the plates are stacked from the bottom in the order of red, eye, key, and sum, and set on the document feed tray.
Here, when the start key is pressed (T901), the feeder
606 first sends the lowermost manuscript, that is, the red plate to the platen of the copier (T902), and after the development with magenta toner (T903) is completed, returns the red plate,
The red version overlaps the top of the manuscript (T904). After this, T9
The same operations as those of 02 to 904 are performed on the eye, key, and sum plates, and a series of procedures is completed.

Third Embodiment The γ correction data in the image processing circuit 107 in the first embodiment is set so that magenta, cyan, yellow, and black are developed in the order of toner to reproduce an image faithful to a document. . Therefore, in order to reproduce an image faithful to the original document with an electrostatic transfer type copying machine using the color-separated plate and the color-separated plate as a document, a gamma for plate inspection is required.
It is desirable to have correction data.

In the present embodiment, from such a viewpoint, the γ correction data of the first embodiment is adaptively changed to one for normal use and one for plate inspection. That is, this embodiment has correction data for the plate inspection mode in addition to the normal mode, and when the plate inspection mode is selected, the γ correction table is created based on the data.

FIG. 10 is a circuit block diagram relating to gamma correction of an image signal according to the present embodiment.

Here, reference numeral 1001 denotes a dual port RAM, which stores gamma correction data from the gamma correction table 1004a held in the ROM 1004 via the address bus 1002 and the data bus 1003 by the CPU 100 prior to the image forming operation. During the image forming operation, the image signal before the γ correction is accessed as an address via the bus 1005 to the γ correction table, and the addressed data is output as the image signal data after the γ correction via the bus 1006. .

Various resolutions from 65 lines, 133 lines to 1200 lines can be considered for printing. In order to flexibly respond to such a large number of requests, it is desired to prepare a plurality of types of γ correction data. For example, for a low resolution version, binarization may be performed, but for a high resolution version, a smooth γ correction curve is more desirable. Therefore, as the gamma correction data in the ROM 1004, each of the normal mode gamma correction table and the plate inspection mode gamma correction table can have the gamma correction data 1004a corresponding to various resolutions.

At this time, the resolution can be determined by: • Direct instruction from the operation panel by an operator • Automatic reading of the frequency of halftone dots on the scanning line • Determination of the luminance histogram of the image and determination from the variance of the luminance distribution (brightness / darkness) If the distribution is extremely large, the resolution is low.)

Further, in the embodiment shown in FIG. 4, the development for one color is repeated by operating the switch. However, the invention is not limited to this, and a timer may be provided so that the time measured by the timer is longer than that of the normal copy. Good.

[Effects of the Invention] As described above, according to the present invention, the normal print mode,
In each of the plate inspection modes, it is possible to reduce the size of the apparatus after realizing a suitable correction process corresponding to various resolutions.

[Brief description of the drawings]

FIG. 1 is a sectional view showing the structure of a copying machine according to an embodiment of the present invention, FIG. 2 is a block diagram showing a control system of the copying machine shown in FIG. 1, FIG. 4 and 8 are diagrams showing display examples on the display unit 319 of the operation unit in FIG. 3, FIG. 5 is a flowchart showing a control procedure in the first embodiment, and FIG. 6 is a copying machine in the second embodiment FIG. 7 is a perspective view of an original feeder, FIG. 9 is a time chart showing an operation in the second embodiment, and FIGS. 10A and 10B are circuit diagrams for explaining gamma correction of an image signal. is there. In the figure, 100 CPU CPU, 101 ROM, 102 RAM, 103 I
/ O, 104: Transfer drum HP sensor, 105: Pulse encoder, 106: BD signal generation circuit, 107: Image processing circuit,
Reference numeral 108 denotes a pre-registration sensor, 109 denotes a manual feed length detection sensor, 110 denotes a developing device motor controller, 112 denotes an optical motor controller, and 114 denotes a transfer drum sensor.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 1/40-1/409 G03G 15/01 H04N 1/46-1/64

Claims (1)

(57) [Claims] 1. An image processing apparatus comprising: a correcting unit for performing a correction process on a color image signal of a plurality of components; and a printing unit for performing a full color print using the corrected color image signal. Instruction means for switching between the normal print mode and the plate inspection mode; and when the normal print mode is instructed, selectively selects correction processing data from correction processing data for the normal print mode provided for each resolution. Control means for selectively setting the correction processing data to the correction means from the correction processing data for the plate inspection mode provided for each resolution when the plate inspection mode is instructed. An image processing apparatus comprising: