JPH046561A - Film printer - Google Patents

Abstract

PURPOSE:To produce process film capable of performing tone display with high definition in spite of low image resolution by controlling a time for irradiating with the spot of light within a main scanning picture element cycle with the spot of the light in accordance with image data provided with multilevel information at the time of scanning by a scanning means. CONSTITUTION:The direction of a beam 4 emitted from a semiconductor laser 1 is changed by a polygon mirror 2 which is driven to be rotated by a motor 3 so as to scan on the scanning line 6 of a film 5. Meanwhile, the film 5 is carried in a direction shown by an arrow (b) by carrying rollers 7a - 7d which are rotated by a rotation driving means. And at the time of recording the image data provided with the multilevel information by performing raster scanning with the spot of light, the time for irradiating with the spot of the light within the picture element cycle of scanning with the spot of light is controlled in accordance with the image data. Then, an exposure area is changed every picture element on the film 5 in accordance with the corresponding image data. Thus, the high image quality can be obtained in spite of the low image resolu tion.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a film printer that outputs a plate-making film for printing, for example.

[Prior Art] Currently, a number of steps are required from the time a designer or editor creates a manuscript until it becomes an actual printed matter. The flowchart is shown in Figure 3. When a designer or editor creates a manuscript and submits it to a printing shop, the work is divided into the text section and the photo section. , select 9 font sizes and fonts, and write each character in a designated location on phototypesetting paper.

Next, paste the photographic paper obtained by photosetting onto the mount according to the layout, write various lines as necessary, paste illustrations and marks, etc., then photograph the resulting mount with a camera, Produce a plate-making film.

On the other hand, in the photography department, if it's a color photo, it's red or blue.

Apply a green filter, then apply a halftone screen,
Create halftone films for cyan, yellow, and magenta. In addition, we will create a dot film for foreigners to capture some of the shadows in photographs. In recent years, processing in this photography department has been done by scanning a laser beam across the document, photoelectrically converting the light that has passed through or reflected from the document, and calculating the resulting signals to perform color separation, rather than photographing the document with a camera. and shading,
Furthermore, a device (scanner) is used that exposes the film to laser beam scanning to produce a halftone film.

The character plate-making film and halftone dot film obtained as described above are laid out on a mask film, and the separated letter plate-making film and halftone dot film are assembled into one film. This is called a collection.

The film obtained from the collection is printed onto a 23rd plate to create a proofing plate, which is then run through a proofing machine and printed.

Designers and editors check the printed material, and if it is correct, print it out, and if corrections are necessary, go back to the process as necessary. For example, if the font or size of the text is different, the process goes back to the phototypesetting process, and if the colors of the photo are different, the process goes back to color separation and printing.

As mentioned above, before printed matter is produced, it goes through various processes by various people. Therefore, it takes several days, and errors in instructions, work errors, etc. are likely to occur, which causes the process to take even more days. Of course, the cost is also high.

[Problems to be Solved by the Invention] Computerization has been progressing in recent years in order to improve the above-mentioned points. The above-mentioned scanner in the photography department is one such example, but phototypesetting has also been computerized, and there are computerized phototypesetting machines that specify text, size, font, layout, etc. on a computer, and then record directly onto film.

Furthermore, although it is a very expensive device, there is a device that phototypes the text portion or combines the text portion and the photo portion and records it directly on film. One of the reasons why it is so expensive is the lack of detail in the photography department. Halftone dot pitch is 100-200dpi
(dot par 1 nch) However, since it is necessary for each halftone dot to have area gradation, when recording on film, one halftone dot is composed of a plurality of dots. Therefore, in order to obtain a high-quality halftone film, 2000 to 300
A film printer with a resolution of 0 dpi is required. On the other hand, the length part is 400~100d because there is no gradation expression.
Get sufficient quality with your Pi film printer.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a film printer capable of solving the above-mentioned problems and producing a plate-making film capable of expressing high-quality gradations even at low resolution.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a scanning means for raster scanning a point of light on a film, and a scanning means for raster scanning a point of light on a film, and a scanning means for raster scanning a point of light on a film. and control means for controlling the irradiation time of the light point within the main scanning pixel period of the point.

[Function] According to the present invention, when recording image data having multivalued information by raster scanning a light point on a film,
The time during which the light spot is irradiated within the pixel period of the scan of the light spot is controlled in accordance with the image data, and as a result, the exposed area is varied for each pixel on the film in accordance with the corresponding image data.

[Embodiment] FIG. 1 is a conceptual diagram of the present invention, and FIG. 2 is a block diagram of a circuit that controls it.

In FIG. 1, a beam 4 emitted from a semiconductor laser 1 is deflected by a polygon mirror 2 rotated by a motor 3, and scans a scanning line 6 on a film 5. On the other hand, the film 5 is transported by transport rollers 7a, 7b, 7c rotated by a rotational drive means (not shown).
, 7d in the direction of the arrow.

With the above configuration, the film 5 is exposed two-dimensionally to laser light. In this process, the light emission of the semiconductor laser 1 is ON-OFF controlled to form exposed and unexposed areas on the film 5.

Next, the ON-OF of the semiconductor laser 1 which is a feature of the present invention
The F control means will be explained using FIGS. 2, 4, and 5. The clock from the clock generator 21 is input to the main scanning counter 22, which counts the number of pixels in the main scanning and generates a pulse of the period. The 1/4 frequency divider 23 divides the frequency of the signal and generates a signal that becomes "High" once every four main scanning periods. The signal is ANDed with the clock from 21 by an AND gate 24 to produce a video clock. These relationships are shown in FIG.

An external device (not shown) sends out image data in synchronization with the video clock. The image data in this case is 8-bit data with gradation data. The switch S receives a signal from the 1/4 frequency divider 23, and when the signal is "High", it is switched to the a side, and when it is "Low", it is switched to the b side. Therefore, image data input from an external device in synchronization with the video clock is
The signal is input to the line shift register 25. The line shift register 25 is composed of the same number of shift registers as the number of main scanning pixels, and after storing the main scanning image data, the switch S is switched to the b side, and the output of the line shift register 25 is shifted to the line shift register 25. It is input to the register 25.

With the above configuration, certain main scanning image data is repeatedly input to the D/A converter 26 four times. The D/A converter 26 converts the input image data into an analog signal.

On the other hand, the triangular wave generator 27 inputs the clock from the clock generator 21 and generates a triangular wave signal having the same period as this clock. By comparing this triangular wave signal and the analog signal from the D/A converter 26 in a comparator 28, a pulse width modulation signal corresponding to the image data is obtained as an output of the comparator 28. These relationships are shown in FIG.

The signal from the comparator 29 is input to the driver 29 of the semiconductor laser 1 to control the semiconductor laser 1 on and off. By controlling the laser in this manner, it is possible to obtain an exposure state of a different area on the film every four sub-scans as shown in FIG. 6 by pulse width modulation according to the image data.

5...Main scanning line, 6...Film, 7...Conveyance roller [Effects of the invention] The present invention has made it possible to obtain high image quality even with low resolution.

[Brief explanation of drawings]

Fig. 1 is a conceptual diagram of the device of the present invention, Fig. 2 is a circuit block diagram of the device, Fig. 3 shows the process of producing printed matter, and Figs. 4 and 5 are diagrams showing timing charts of signals in the device. FIG. 6 is a diagram showing the exposure state of the film. 1... Laser 2... Polygon mirror 3... Motor, 4... Laser light,

Claims (1)

[Claims] 1) A scanning means for raster scanning a point of light on the film, and a time period during which the point of light is irradiated within a main scanning pixel period of the point of light according to image data having multi-value information when scanning with the scanning means. A film printer comprising a control means for controlling.