JPS5937544A - Picture duplicating device - Google Patents

Abstract

PURPOSE:To shorten an operation time and to reduce the cost of materials by forming a mesh negative plate film which has dots varying in size and density with the density of a picture on an original. CONSTITUTION:An electric signal (j) is inputted to a controller 13 and inputted to a control signal genrator 16 which generates control signals (l) and (m) for controlling the 1st modulator 14 modulating light (b) from a light source 12 for exposure and the 2nd modulator 15 connected in series with the 1st modulator 14. The control signal (l) is inputted to the 1st modulator 14 and the other control signal (m) is inputted to the 2nd modulator 15. Light (d) modulated by the modulators 14 and 15 illuminates a photosensitive film 4 for exposure and the film is processed by development to obtain the mesh negative plate film having dots which vary in size and density with the picture density of the original. Thus, the operation time is shortened and the cost of materials is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Conventionally, an original is photoelectrically scanned to convert the image information of the original into an electrical signal, and based on the converted electrical signal, light from an exposure light source is controlled, and the controlled light is reproduced. Devices that form a duplicate image by exposing a substrate for printing are known, and a typical example is a plate-making scanner.

FIG. 1 is a schematic explanatory diagram of a plate-making scanner. Generally, a document (2) is attached to the document drum (1), a photosensitive film (4) is attached to the exposure drum (3), and the document (2) is attached to the exposure drum (3).
) is reproduced on a photosensitive film (4) as a substrate for reproduction. Formation of a duplicate image in this case is performed as follows. The original (2) is irradiated by a light source for transparent originals (5) or a light source for reflective originals (6) depending on whether it is a transparent original or a reflective original, and light (a) is transmitted through the original or reflected from the original.
) is input to the document scanning head (7), where it is color separated by a color separation filter and photoelectrically converted. The light (al) transmitted through or reflected from the original contains image information of the original, and the image information is converted by the original scanning head (7) into the form of an electrical signal containing image information.

The electric signal 1+ thus obtained is processed by an electric double signal processing device (
8).

The electrical signal processing device (8) performs necessary processing such as gradation curve control, UCrt (undercolor removal) calculation, sharpness calculation, color correction calculation, etc. based on the input electrical signal (i), and produces the final result. The electric signal fj) to be outputted to the control device (9) is calculated and the electric signal (j) is input to the control device (9).

The control device (9) is for controlling the exposure scanning head (IO) based on the electrical signal (j). The document drum il+ rotates in the direction of the arrow (A) and the document scanning head moves in the direction of the arrow σ3) so that the entire document can be scanned, and likewise the exposure drum (3) moves in the direction of the arrow fc). The rotating exposure scanning head 00) moves in the direction of the arrow CD+ so that the entire photosensitive film (4) can be exposed.

As described above, the reproduced image formed by photoelectrically scanning the original and exposing it to light on the exposure drum is generally a so-called halftone dot expressed in JS with the same density corresponding to the density of the original image. These are halftone original films such as negative chips and halftone printing, or continuous tone original films such as so-called continuous tone negative chips and continuous tone printing which are expressed by density changes corresponding to the density of the original image.

FIG. 2 is an explanatory diagram of a conventional method of this exposure mechanism, in which a control signal fkl output from a control device (9) is input to a modulator (11). On the other hand, light (b) emitted from a light source (121) such as an argon laser is also input to this modulator (11), modulated according to the control signal (k), and output as exposure light (cl) onto the document drum (3). The photosensitive film (4) set in is exposed.

In this case, in the device for producing halftone original film,
The modulator (11) changes the light ttb+ according to a control signal (kl) that performs so-called on-off control of whether or not all or part of the light (bl is placed on the optical path), and this changes the density of the original. A duplicate image is obtained in which the size of the halftone dots changes correspondingly.

In addition, in an apparatus for producing a continuous tone original film, the modulator (+1) is used as a control signal +k to control the intensity of the light (b).
), which changes the intensity of the light (b) according to the density of the original, thereby obtaining a reproduced image whose density changes in accordance with the density of the original.

A halftone original film or a continuous tone original film is produced in the manner described above, and the films thus obtained are used individually or in combination for producing a printing plate.

By the way, one of the gravure printing methods is known as a dot gravure printing method, and one of the methods is a known method in which both the cell size and cell depth of the gravure plate are changed according to the density of the original. There is. Conventionally, one of the methods for creating such a gravure plate is to align a so-called net negative chip and a continuous tone negative chip, overlap them, print them in close contact with a photosensitive film, and then process them to determine the size of the halftone dots. A method is known in which a net positive chip with varying concentrations is prepared, the net positive chip is baked in close contact with a carbon chip to form a resist, and the resist is used to etch a copper cylinder.

However, this method requires two types of original film, a halftone original film and a continuous tone original film, which are produced using the prepress scanner mentioned above and other devices, and therefore, it takes a lot of time and material costs to create these two types of original film. There is also the disadvantage that it requires more time and material costs to combine them into a single sheet.

The present invention eliminates the above-mentioned drawbacks and provides a novel image duplicating device capable of producing a halftone original film in which the size of halftone dots and the density of individual halftone dots change depending on the density of the image of the original. This is what I am trying to do.

That is, the present invention photoelectrically scans the original as described above, converts image information of the original into an electrical signal, controls light from an exposure light source based on the converted electrical signal, and uses the controlled light as a copying base. In an image duplicating apparatus that forms a duplicated image by exposing a material to light, a first control unit controls whether or not all or part of the light from the exposure light source is placed on an optical path based on the electric signal. A modulator and a second modulator for controlling the intensity of light from the exposure light source based on the electrical signal are connected in series, and the two connected modulators are controlled based on the electrical signal. The present invention relates to an image duplicating apparatus characterized in that it is equipped with a control device for controlling the image.

The general structure of the image duplicating device of the present invention is as shown in FIG. 1, but the processing of the electrical signal U) output from the electrical signal processing device (8) was explained with reference to FIG. 2. This is different from traditional processing methods.

FIG. 3 is a schematic explanatory diagram of the exposure part of the apparatus of the present invention,
The electrical signal ('') is input to the control device 03). The electric signal (il) input to the control device (13) is the exposure light source (1
2) a control signal (e) that controls a first modulator 04 that modulates the light (bl) and a second modulator (one) connected in series to the first modulator (14); The control signal 1e)) generated by the control signal generator (16) is input to the first modulator (14) and is input to a control signal generator (16) that generates the signal M. ) is input to the second modulator (151).

Next, to explain the modulator, the first modulator (the circle is the light (bl) emitted from the exposure light source (+21) is controlled by a control signal (to put all or a part of it on the optical path or not to put it on the optical path). It changes the size of the halftone dots formed on the duplication base material. For example, in the case of outputting a positive image, control is performed such that the higher the density of the original, the larger the halftone dots. A conventionally well-known modulator can be used.The second modulator (151) receives the light tb' modulated as described above by the first modulator (14).
It changes the strength of + according to the control signal -,
For example, in the case of outputting a positive image, control is performed such that the strength of the base of the document where the density is high is increased. As such a modulator, a conventionally well-known modulator can be used.

FIG. 4 is an explanatory diagram of one embodiment of the exposure portion of the apparatus of the present invention. In FIG. 4, the light emitted from the exposure light source (121) is divided into 10 parts by the mirror light and becomes 10 pieces of light (BL) and enters the first modulator (1 piece).

The first modulator (14) has io modulators (14a) to (
+4j), and the -force control signal (1) consists of control signals (jJ~(J?+o), which respectively control the modulators (14a)~(14j).The control signal (1)
l! +) to (l!+o) are either on or off signals depending on the density of the original image. The modulators (1, 4a) to (+4j) are the control signals (E,) to
(I!1o) causes the state to be either on or off; when a modulator is on, it passes the light that has entered the modulator; when it is off, it passes the light that has entered the modulator. do not pass through. By doing so, the size of the halftone dot can be changed depending on the density of the original image.

The light (bl passing through the first modulator Q4) enters the second modulator (15). The second modulator (!9 is composed of 10 modulators (15a) to (15'') The example force control signals consist of control signals (ml) to (m, .), which respectively control the modulators (15a) to (15J).

The control signals (ml) to (mho) are signals for controlling the intensity of light depending on the density of the original image, and are (ml) to (m,).

) have the same value. The intensity of the light entering the modulators (15a) to (15'') is changed by the control signals (m,) to (mho). The light thus passed through the first modulator and the second modulator is used for halftone dot formation.

That is, the light (d) consisting of 10 divided lights is used to form individual halftone dots and is exposed onto the reproduction substrate through the lens +L+.

Note that which light is turned on and which light is turned off by the first modulator depends on the screen angle of the halftone original film to be output, but this control can be done using a known method. I don't often go into details.

In this way, the first modulator (14) and the second modulator (151
The light modulated by (dl) is exposed onto a photosensitive film (4) as a base material for duplication, and the exposed photosensitive film (4) is developed to change the dot size and density. In both cases, a halftone original film whose density changes depending on the image density of the original is obtained.

The halftone original film thus obtained is used to make gravure printing plates in which both the cell size and depth vary as described above.

The first modulator and the second modulator may be connected so that either one receives the light from the exposure light source (121) first.

Further, the halftone original film outputted by the apparatus of the present invention may have a halftone dot structure for offset or a halftone dot structure for gravure.

Further, the base material for duplication can be a photosensitive film, in which case a halftone original film is obtained, and the base material for duplication can also be a synthetic resin layer, in which case a laser beam is used as the light source. By evaporating the synthetic resin layer, a gravure plate in which both cell size and depth can be directly obtained can be obtained.

As described above (according to the apparatus of the present invention, a halftone original film in which the size of halftone dots and its density change according to the image density of the original can be obtained directly from the original, and compared to the conventional method, It is possible to shorten working time and reduce material costs.Furthermore, according to the present invention, resin gravure plates with different cell depths and cell sizes can be directly obtained by the previous control, which is different from conventional methods. The device can be much simpler than the mechanical engraving method.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a plate-making scanner, FIG. 2 is an explanatory diagram of the exposure part of a conventional image duplication apparatus, FIG. 3 is an explanatory diagram of the exposure part of the image duplication apparatus of the present invention, and FIG. 4 is an explanatory diagram of the exposure part of the image duplication apparatus of the present invention. 2A and 2B are explanatory diagrams of an embodiment of an exposure portion of the image duplicating apparatus of FIG. (1)...Original drum (2)...Original (3)
...Exposure drum (4)...Photosensitive film (5)...Light source for transparent originals (6)...Light source for reflective originals (7)...Original scanning head (8)...
・Electrical signal processing device (9)...control device (
10)...Exposure scanning head 0υ...Modulator
(121...Light source (13)...Control device
(+41...First modulator (15)...Second modulator (16)...Control signal generator Patent applicant Toppan Printing Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] +11 The original is photoelectrically scanned to convert the image information of the original into an electrical signal, the light from the exposure light source is controlled based on the converted electrical signal, and the controlled light is exposed onto the reproduction base material. In an image duplicating apparatus for forming a duplicate image, a first modulator that controls whether or not all or a part of the light from the exposure light source is placed on an optical path based on the electric signal; and a second modulator for controlling the intensity of light from the exposure light source based on the electric signal, and a control device for controlling the two modulators connected in series based on the electric signal. An image duplicating device characterized by comprising: