DE2039440A1 - Optical device for the separate and complete mapping of seamlessly touching grid fields - Google Patents

Description

ARTHUR KLEMT KG.
8031 Olehing, Schwalbeneck 5

Optical device for the separate and complete mapping of seamlessly touching grid fields

The invention relates to an optical device for the separate / and 'complete mapping of seamlessly touching grid fields of an image area onto assigned oneself not completely touching image fields.

In a number of technical areas, e.g. in the automatic reading and classification of characters, the problem arises, a picture plane that is in thought, itself seamlessly touching triangular, square or hexagonal grid fields is divided optically in such a way on assigned light-absorbing Map areas that the light each one of the imaginary grid fields on the respectively assigned light-absorbing surface, i.e. the assigned imaging field. as light-sensitive imaging fields are used in most cases photoelectric converters used. So it must each of the imaginary grid fields on a separate photoelectric

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Transducers are mapped. The main difficulty arises from that the photoelectric converters available today. sufficiently small geometrical dimensions in general have circular photosensitive surfaces, the diameter of which is considerably smaller than the diameter of the photoelectric converter as a whole, i.e. around the actual photosensitive Around the area there are light-insensitive areas up to the housing wall of the photoelectric converter. For side-by-side arrangement a plurality of photoelectric converters, as they are divided into imaginary grid fields for scanning a Image area is required, but the dimensions of the converter housing are decisive. Accordingly, in a direct Projection of the image onto the photoelectric arranged next to one another in accordance with the imaginary rasterization of the image area Transducer considerable gaps, i.e. areas in the plane of the transducers arranged next to one another in which the incident Light is not detected. En it is clear that this is a factor of uncertainty and is a significant source of error for a proper scanning of the presented image.

The invention is based on the object of a

k to create an optical device that allows, with a large number of seamlessly touching grid fields of an image area and a corresponding number of non- seamlessly touching image fields, the entire light coming from an imaginary grid field onto the respective assigned image field, e.g. the light-sensitive area of an assigned one photoelectric converter, in which the light falling on an imaging field is equal to or proportional to the illumination intensity averaged over the assigned grid field, in the case of photoelectric converters the voltages output are really proportional to the intensity of the light coming from the entire grid field in question , and which are still easy and cheap to produce

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This object is fully achieved by the invention Scope solved.

The invention relates to an optical one Device for the separate and complete mapping of seamlessly touching grid fields of an image surface onto assigned mapping fields that do not touch each other completely is characterized by a light guide block of light-guiding rods combined in packets, the number of which corresponds to the number the Pasterfeider agrees, their cross-sectional shape and Arrangement at their light entry end of the grid division corresponds to the image area to be depicted, and its light exit ends are designed and arranged such that all rays passing through a light-conducting rod in the assigned mapping field fall.

In many cases it is useful for the light to exit of the light-conducting rods designed as lenses

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To bring about parallel incidence of light into the individual light-guiding rods of the light guide block, "wake-up." mSBig one for all light-conducting rods common lens attached.

The individual light-conducting rods can one have a constant cross-section over their length and to form of the light guide block in several layers of several Rods can be arranged parallel to one another, or they can be conical and joined together to form a conical light guide block or they can be curved, with the preferred configuration depending on, among other things, the size ratio of image area and image fields.

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The light-conducting rods preferably consist of Glass or a translucent plastic, being by use of colored glass or colored translucent plastic, a filter effect can be achieved at the same time.

Each light-conducting rod expediently has a highly reflective outer surface.

The invention is described below in conjunction with the attached drawings on the basis of preferred embodiments further explained.

FIG. 1 shows an optical fiber block designed according to the rules of the invention.

Figure 2 shows a light guide block made of light-guiding Rods with a constant cross-section over their length.

FIG. 3 shows a light guide block made of conical light-guiding rods.

FIG. 4 shows a light guide block made of curved light-guiding rods.

FIG. 5 shows a light guide block with a lens attached to the light entry side.

Figure 6 illustrates the arrangement and operation of a light guide block according to the invention in conjunction ir.it an image area divided into imaginary grid fields and a corresponding number of image fields in the form of photoelectric converters.

According to Figure 1, the light guide block 10 consists of a plurality of light-guiding rods 11, which lie close to one another are assembled like a packet to form the light guide block.

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The individual light-conducting rods can, for example, to the Block glued together or held together by a jacket. Each light-conducting rod 11 consists of one: good light-conducting material, preferably glass or a plastic. Since the incident in a single light-conducting rod Light guided as completely as possible through this rod and should not flow into adjacent bars is a to strive for high reflectivity of the outer surface of each light-guiding rod. This can be done to a sufficient extent e.g. can be achieved by polishing the outer surfaces of the individual rods. Of course, the bars can also be used outside in special cases be mirrored. The particular training chosen for the Rods is of no major importance as long as good light conductivity is guaranteed and the possibility of light loss into neighboring rods is largely excluded.

The light-guiding rods 11 are in all embodiments at their light entry end 12 designed and arranged so that the lines of contact between the individual Patterns formed on the light inlet soap 13 of the rods Light guide blocks 10 corresponds to the imaginary division of the image area to be imaged into grid fields. Is it, for example around one divided into imaginary square grids Image area, the individual light-guiding rods 11 have a light entry end 12 of square cross-section and there are as many light-guiding rods combined to form the light guide block 10, as the image area includes imaginary grid fields. Needs it doesn't necessarily have to be a regular grid; if, for example, individual grid fields of larger dimensions are provided, e.g. the area of two, three or four of the The light guide block contains the other grid fields accordingly IO at the same place a light-guiding rod accordingly larger dimensions, the light entry surface of which the

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Sunune of the light entry surfaces of two, three or four of the corresponds to other light-conducting rods.

As a result of the coincidence of the light entry ends the light guide-r. the rods formed pattern with dor The imaginary division of the DLid area into grid fields only occurs in each light-conducting rod from the assigned grid field incoming light, but this completely. The light goes through the individual rods and occurs because a transition into neighboring rods due to the high reflectivity of the outer surface of the individual Rods is prevented from being exactly a '"separated according to the from The light intensities coming from the individual grid fields emerge again at the light exit ends 14 of the individual rods. From there it falls on the mapping fields 15 indicated schematically in FIG. 1. The whole of an imaginary grid field arrives incoming light and only this on the assigned image field. It is through appropriate training and arrangement the light exit ends 14 of the light-guiding rods 11 are not more required that the imaging fields 15, such as the light-sensitive areas of photoelectric converters, without gaps touch. Nevertheless, all of the light is captured.

There are numerous for the formation of the individual light-guiding rods and their assembly to form the light-guide block Possibilities of variation, whereby the preferred embodiment in the individual case is determined by the proportions of the image to be depicted Image area, light guide block and light-absorbing image fields, e.g. the light-sensitive areas of photoelectric converters'. Three preferred embodiments are shown in FIGS. 2, 3 and 4.

In the embodiment according to FIG. 2, the light-conducting rods 11 have a constant cross-section over their length. They are in several of the imaginary grid layout

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division of the image area corresponding layers from each of several. Rods arranged parallel to each other. To the full cross-sectional area of each light-conducting rod 11 on your assigned To image the imaging field 15, i.e. the entire light coming through a light-conducting rod from the light exit end To throw the imaging field, the light exit ends 14 of the individual light-conducting rods 11 are designed in the shape of a lens. A lenticular design is always provided when the imaging fields are smaller than the cross-sectional areas the light-conducting rods on the light exit side. The lenticular Training can be such that the entire through the. concerned light-guiding rod is practically bundled to a point in the plane of the imaging fields, it is sufficient but also a reduction to such a diameter, that in any case all light on the imaging field, e.g. the light-sensitive surface of a photoelectric converter, is thrown.

In the embodiment of Figure 3 are conical light-conducting rods 16, the diameter of which increases from the light entry end 12 to the light exit end 17, to a conical one Light guide block 18 summarized. Also here is through that strong reflectivity on the outer surfaces of each light-guiding rods ensured that the in a light-guiding Rod entering light into neighboring rods without loss reaches the light exit end of this rod and then to the relevant imaging field 15. One such training is For example, useful if the imaging fields 15 a larger area requirement than the light entry ends 12 of the light-guiding Have bars. In this embodiment, too, are Light exit ends 17 of the light-conducting rods 16 are designed in the shape of a lens. '

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In special cases, the liclitleitonden rods of course also one extending from the light entry probe to the light exit end have a conical tapering shape.

In the embodiment of FIG. 4, curved light-guiding rods 19 are combined to form a light-guiding block 20. The high reflectivity of the outer surface of the individual light-conducting rods also prevents light loss here in the nearby areas. As a result of the fan-like divergence of the rods, the light exit ends 21 can be flat here, e.g. if the imaging fields 15 have the same cross-sectional shape and size as the light exit ends or are larger. Even This embodiment is particularly suitable when the area requirement of the imaging fields 15 is greater than the light entry side of the light guide block is. The space 22 between the individual light-guiding rods can be completely filled with a filler material or partially filled in to obtain a compact light guide block.

U.N; To ensure a clean image of the scanned image surface on the light entry side 13 of the light guide block 10 and thus, a completely unaltered light guide to the graphs in Fig W dungsfeidern, the light path at the light entrance side should be approximately parallel to the longitudinal axis of the light conducting rods. If necessary, for this purpose, for example according to FIG. 5, a lens 23 can be attached in front of the light guide block. This applies to all of the embodiments explained above.

. FIG. 6 illustrates the arrangement and mode of operation of a light guide block according to the invention on one Example from the plain text reading. It is assumed that an image area, which in 4 χ 6 = 24 imaginary square grid fields is divided on the photosensitive surfaces of photoelectric converters to be mapped. The case diameter customary, suitable photoelectric wall

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ler is about 3 mm, the diameter of the photosensitive Area on the other hand only about 1 mim.

The overall arrangement comprises the image surface 24, a lens or a lens system 25, one designed according to the invention Light guide block 26 of twenty-four light-guiding rods 27 with lens-shaped light exit ends 28 and a common ancillary lens 29, and four hundred and twenty behind photoelectric converters arranged at the light exit ends Lens system 25 imaged on the light entry side of the light guide block 26, the ancillary lens 29 being that of the lens system coming rays according to the direction of travel of the light-guiding Makes bars 27 parallel.

The light guide block 26 itself consists of light-guiding rods 27, the cross-sectional shape and arrangement of which on the The light entry side of the block corresponds to the imaginary grid of the image area 24 to be imaged, that is to say here from twenty-four square light guide rods in six layers of four each Rods are arranged. The absolute size of the cross-sectional areas of the light-conducting rods 24 is chosen so that at one that corresponds to the imaginary grid of the image surface 24 Arrangement of the photoelectric converter 30, the mutual spacing of the center lines of the light-guiding rods 27 with the mutual distance between the centers of the light-sensitive Areas of the photoelectric converter 30 coincides. That on the entrance side of the light guide block 26 projected light goes, divided into the individual light-guiding rods 27 in exact correspondence with the imaginary grid of the image surface 24, through the light-conducting rods and then onto the associated photoelectric converter 30. The light exit end 28 of each light-conducting rod 27 is designed as a converging lens, so that the whole is back through a light-conducting rod.

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light passing through to the light-sensitive surface of the associated Converter is thrown.

The optical device according to the invention is therefore simple, reliable and cost-saving achieves that seamlessly touching grid fields of an image area are separated and completely assigned to each other and not completely touching image fields are mapped, whereby for example in the explained application in the plain text reading it is ensured that the voltage emitted by the photoelectric converter assigned to a specific grid field is exactly proportional to the mean light intensity of the relevant grid field, regardless of how the light intensity is distributed on this grid.

By using light-conducting rods made of colored glass or colored translucent plastic, an adaptation to different original images, e.g. image areas with dark characters on a light background or light characters on a dark background, also in conjunction with colored characters and / or colored background, as well as an adaptation to the Farbempfind- length friendliness of imaging fields, such as the photoelectric converter can be achieved, would be without additional filters required.

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Claims (8)

- Ii - Claims Ι, Optical device for separate and complete Imaging of seamlessly touching grid fields of an image area on assigned, not completely touching image fields, characterized by a light conductor block (10, 18, 20, 26} made of light-conducting bundled together Rods (11, 16, 19, 27), their number with the number of the grid fields, their cross-sectional shape and Arrangement at its light entry end (12) of the grid division corresponds to the image area (24, FIG. 6) to be imaged, and its light exit ends (14, 17, 21, 28) are designed in this way and are arranged that all rays passing through a light conducting rod into the associated Image field (15, 30) fall. 2. Device according to claim 1, characterized in that that the light exit ends (14, 17, 28) of the light-conducting rods (11, 16, 27) are designed as lenses. 3. Apparatus according to claim 1 or 2, characterized characterized in that a lens (23) is attached to the light entry side (13) of the light guide block (1O). 4. Device according to one of claims 1 - 3, characterized in that the individual light-conducting rods (11) have a constant cross-section over their length and are arranged in several layers of several rods lying parallel to one another. 5. Device according to one of claims 1 - 3, characterized in that the individual light-conducting rods 109887/1027 (16) are conical and assembled to form a conical light guide block (18). 6. Device according to one of claims 1-3, characterized in that the individual light-conducting rods (19) are curved. 7. Device according to one of claims 1-6, characterized in that the light-conducting rods (11, 16, 19, 27) are made of glass or translucent plastic and each light-conducting rod has a highly reflective outer " has area. 8. Device according to one of claims 1-7, characterized in that the light-conducting rods (11, 16, 19, 27) are made of colored glass or colored translucent plastic. 109887/1027 Blank page