Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C5/00—Photographic processes or agents therefor; Regeneration of such processing agents
  • G03C5/02—Sensitometric processes, e.g. determining sensitivity, colour sensitivity, gradation, graininess, density; Making sensitometric wedges
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
  • G03B27/00—Photographic printing apparatus
  • G03B27/72—Controlling or varying light intensity, spectral composition, or exposure time in photographic printing apparatus

Definitions

• the invention relates to a method for visually checking the reproduction quality of drawing elements which are exposed to light-sensitive photo material by means of a cathode ray tube and elements for carrying out this method.
• the invention relates to the field of typesetting technology, in particular to the field of electronic light typesetting for the production of printed products.
• cathode ray tube for the production of printing templates is found today, e.g. B. in the production of film set, plotters and in the facsimile remote transmission of artwork, such as newspaper pages on telephone lines.
• the full page exposure of Newspaper photo paper or directly on printing plates is e.g. B. another application of the cathode ray tube.
• typesetting by photographic means is becoming increasingly widespread and important in the graphic arts industry. Today it can be assumed that the lead type will be successively replaced by the film type. In addition to the economic and technological advantages of film typesetting, it also has the problem of quality assurance.
• the blackening or density on photo paper should be so high that there is such a high contrast between the drawing element and the paper white that it enables a photographic recording on a graphic film.
• a group contains errors in the mechanical adjustment and positioning of individual letters and entire lines.
• a second group includes errors in the optical transmission, that is in the exposure and development of the text columns.
• This group mainly includes
• Line thickness change and density are two characteristics that run largely parallel, which means that a change in the line thickness can also be expected to change the density.
• the measuring microscopic method uses a microscope that is equipped with an eyepiece screw micrometer. After finding a suitable measuring point, the line width can be read on the scale division in the eyepiece. Since the beginning and end of the line to be measured on the paper column cannot be precisely determined due to the lack of edge sharpness, this method is subject to a certain degree of uncertainty when determining the effective line thickness.
• the degree of area coverage of a grid field exposed on the photo setting machine is measured in order to control the change in line thickness. If the individual points or lines of the grid widen, the area coverage increases, the field appears darker and a higher measured value can be determined with the densitometer.
• the density is continuously scanned across the entire width of the line to be measured with a measuring gap opening of 0.5 to 5 ⁇ and recorded as a function of the location coordinate on a writing instrument connected for this purpose.
• the line width and density can then be measured or read from the recorded density profile.
• control fields consisting of three different raster points, which are combined to form a control field, are exposed by means of the photo setting machine.
• the control field is like the normal text at the beginning and at Exposed at the end of a text column. If conditions occur during the exposure or development process that result in a change in density and line thickness, the control panel can e.g. B. the terms "overexposed” or “underexposed” can be recognized or read, depending on whether it is an increase in the density and line width values or a reduction thereof. If there is no change in density and line thickness, the control field appears as a neutral gray area, which in turn can be easily identified by the naked eye.
• FIG. 1 shows an example of the reproduction of the normal elements used in carrying out the method
• FIG. 2 shows an example of the reproduction of the positive elements used in the implementation of the invention
• FIG. 3 shows an example of the reproduction of the negative elements used in carrying out the method
• FIG. 4 shows a diagram for the percentage area coverage of the elements as a function of the exposure
• Figure 5 shows an example of the correct one Reproduction of normal positive and negative elements
• FIG. 6 examples of underexposure, overexposure and normal exposure of the control fields
• FIG. 7 shows an example of the structure of a normal element
• Figure 8 shows an example of the structure of a
• FIG. 9 shows a further example for the construction of a negative element
• Figure 10 shows an example of the structure of a
• Figure 11 shows another example of the structure of a positive element.
• the present invention now provides three surface elements for controlling the reproduction quality, so-called halftone dots, which differ in their response to changed processing conditions.
• a surface element was designed for each of the three processing areas, which takes advantage of the special circumstances of the area concerned. This behavior can be achieved by incorporating latent reinforcements in the positive element and latent weak points in the negative element. These positions can therefore be described as latent because their effectiveness does not exist in the normal area.
• Figure 1 shows the behavior of the normal element within the entire processing area.
• the normal element changes only slightly within the entire range, ie negative range, normal range and positive range.
• Figure 2 shows that the positive element behaves very similar to the normal element in the negative area, but shows a clear tendency in the positive area to enlarge its area.
• FIG. 3 shows that the negative element also changes very similarly to the normal element in the positive region, but it shows one, unambiguous one in the negative region. Tendency to reduce its area.
• FIG. 4 shows the tonal value behavior of the three elements to one another within a large processing range. The exact structure of the individual elements is shown later with reference to FIGS. 7-11.
• FIG. 6 A control field was realized in FIG. 6, which reveals the terms “overexposed” and “underexposed”, depending on whether the text column was exposed with too high or too low intensity. If the exposure corresponds to the usual values, which the photosetting manufacturer has designated as correct, the control field appears as a neutral gray area.
• Figure 7 shows an embodiment of a normal element that is designed as a halftone dot with closed black coverage. It corresponds approximately to a common grid point, as z. B. in the already mentioned DE-PS 15 97 773 in Fig. 5 is shown.
• FIG. 8 shows an exemplary embodiment of a negative element in which a coherent black surface is present in the center and the latent weak points are arranged around this central surface, for B. checkered like in the form of non-printing small white areas and small black areas.
• FIG. 9 shows a variant of such a negative element, in which the weak points are distributed over the entire grid point, e.g.
• the element can consist of a central white area and strips of black and white areas adjoining this white area.
• FIG. 10 shows an embodiment of a positive element which consists of a central area of closed black coverage and individual small black areas which form reinforcements and are arranged approximately in the corners of a rectangle surrounding the black coverage. The small black areas can have the size of the smallest printable dot.
• FIG. 11 also shows an example of a positive element which, like the positive element of FIG. 9, has a central, self-contained black surface and latent reinforcements arranged in a circle around this surface.
• FIGS. 7 and 10 are exposed as they are shown in FIGS. 7 and 10, i. that is, the percentage of the black area corresponds to the tone value to be imaged. The same applies to the normal element and the positive elements according to FIGS. 9 and 11.
• the black parts of the negative element are reproduced even more weakly, and the small points surrounding the central area are omitted for the positive element.
• the reduction in the proportion of black areas in the negative element is substantially greater than in the positive element, which is why a visually more noticeable change in the tonal value occurs when the negative element is underexposed.
• the combination of negative, normal and positive elements enables the visually recognizable display for over, normal or underexposure, as shown in FIG. 6.
• the normal element hardly changes when overexposed or underexposed, whereas negative and positive elements respond to overexposure or underexposure to different extents.
• the invention is not limited to the examples shown in the aforementioned figures, but the individual elements can be modified within the scope of the invention, but the principle of the present invention is still used.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Silver Salt Photography Or Processing Solution Therefor (AREA)
• Control Of Exposure In Printing And Copying (AREA)
• Analysing Materials By The Use Of Radiation (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6711762

Family Applications (1)

Country Status (3)

Cited By (2)

Citations (4)

• 1980
  • 1980-07-15 JP JP55501600A patent/JPH0235287B2/ja not_active Expired - Lifetime
  • 1980-07-15 WO PCT/DE1980/000103 patent/WO1982000368A1/en unknown
  • 1980-07-15 GB GB8204173A patent/GB2093216B/en not_active Expired

Patent Citations (4)

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