PASSIVE ILLUMINATION DEVICE

Abstract

A passive illumination device for use with at least one light source unit of an image receiver, in particular of a code reading device and/or code verification device, has at least one diffuser unit which is configured for converting light provided by the light source unit into at least substantially diffuse illumination light for an illumination of at least one illumination region and which comprises at least one diffuser element with at least one diffusion shell for a scattering of the light.

Claims

1. A passive illumination device for use with at least one light source unit of an image receiver, in particular of a code reading device and/or code verification device, with at least one diffuser unit which is configured for converting light provided by the light source unit into at least substantially diffuse illumination light for an illumination of at least one illumination region and which includes at least one diffuser element with at least one diffusion shell for a scattering of the light.

2. The passive illumination device according to claim 1, wherein the diffusion shell includes at least one inner surface, which is implemented as a partial surface of an imaginary ovoid.

3. The passive illumination device according to claim 1, wherein the diffusion shell includes at least one inner surface, which is implemented as a partial surface of an imaginary cylinder.

4. The passive illumination device according to claim 1, wherein the diffusion shell includes at least one inner surface, which is implemented as a partial surface of an imaginary conus.

5. The passive illumination device according to claim 1, wherein the diffuser unit includes at least one optical element, which is configured to deflect light provided by at least one light source of the light source unit toward the illumination region.

6. The passive illumination device according to claim 5, wherein the optical element is configured to let light reflected by the illumination region pass at least partially.

7. The passive illumination device according to claim 5, wherein the optical element includes at least one semi-permeable mirror.

8. The passive illumination device according to claim 5, wherein the optical element is embodied as a beamsplitter cube, and the diffuser element includes at least one receptacle for a form-fit holding of the optical element.

9. The passive illumination device according to claim 5, wherein the diffuser unit includes at least one subregion that is configured to feed light provided by the light source into the optical element.

10. The passive illumination device according to claim 9, wherein the subregion is additionally configured to feed light provided by the light source into the diffusion shell.

11. The passive illumination device according to claim 1, wherein the diffuser element is implemented in one piece.

12. The passive illumination device according to claim 1, wherein the diffuser unit includes an outer wall encompassing the diffusion shell completely.

13. The passive illumination device according to claim 1, further comprising a fastening unit for an, in particular removable, fixation of the diffuser unit to the image receiver.

14. A system, in particular a code reading system and/or code verification system, with at least one passive illumination device according to claim 1 and with the image receiver, in particular the code reading device and/or code verification device.

15. The system according to claim 14, wherein all light sources of the light source unit are oriented parallel to one another.

Description

DRAWINGS

[0028] Further advantages will become apparent from the following description of the drawings. In the drawings three exemplary embodiments of the invention are illustrated. The drawings, the description and the claims contain a plurality of features in combination. Someone skilled in the art will purposefully also consider the features separately and will find further expedient combinations.

[0029] It is shown in:

[0030] FIG. 1 a schematic illustration of a system with a passive illumination device and with an image receiver, in an exploded view,

[0031] FIG. 2 a schematic illustration of a fastening unit of the passive illumination device in an oblique view from above,

[0032] FIG. 3 a schematic illustration of a diffuser element of the passive illumination device in an oblique view from above,

[0033] FIG. 4 a schematic illustration of the diffuser element in a sectional view,

[0034] FIG. 5 a schematic illustration of an optical element of the passive illumination device in a view from above,

[0035] FIG. 6 a schematic illustration of a diffusion shell of an alternative passive illumination device in an oblique view from above, and

[0036] FIG. 7 a schematic illustration of a diffusion shell of a further alternative passive illumination device in a sidewise oblique side view.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0037] Of objects present more than once, in each case only one is given a reference numeral in the figures. In the description of the exemplary embodiments, the terms “above” and “below” refer to the customary installation position, in which an object that is to be scanned is arranged below and an image receiver is arranged above.

[0038] FIG. 1 shows a system 38a, in the present case a code reading and/or code verification system. The system 38a comprises an image receiver 14a. The image receiver 14a is embodied as a code reading device and/or code verification device known from the prior art. The image receiver 14a comprises a light source unit 12a. The light source unit 12a comprises light sources 28a, 29a, which are arranged in the shape of a planar circle. The light source unit 12a comprises six light sources 28a and two light sources 29a. Alternatively, a different number of light sources 28a, 29a and a different arrangement of the light sources 28a, 29a would also be conceivable. All of the light sources 28a, 29a are oriented parallel to one another. The light sources 28a, 29a are implemented identically to one another, such that only one of the light sources 28a, 29a will be described below.

[0039] The system 38a comprises a passive illumination device 10a, parts of which are illustrated in detail in FIGS. 2 to 5.

[0040] The passive illumination device 10a is configured to be used with the light source unit 12a. The passive illumination device 10a comprises a diffuser unit 16a. The diffuser unit 16a is configured to convert light provided by the light source unit 12a into diffuse illumination light for an illumination of an illumination region 18a (cf. FIGS. 1 and 4). The diffuser unit 16a comprises a diffuser element 20a, which is shown in detail in FIG. 4. The diffuser element 20a is implemented completely of a translucent material. The diffuser element 20a is made of polyamide. Alternatively, the diffuser element 20a could be made of other materials deemed expedient by someone skilled in the art, for example other synthetic materials, in particular ABS, PP, PU and/or PC, and/or quartz glass. The diffuser element 20a is embodied in a one-part implementation. The diffuser element 20a has been produced via a 3D printing method.

[0041] The diffuser element 20a comprises a diffusion shell 22a. The diffusion shell 22a servers for a scattering of the light provided by the light source unit 12a for the purpose of providing at least a light fraction of the diffuse illumination light. The diffusion shell 22a has an inner surface 24a. The inner surface 24a is formed as a partial surface of an imaginary sphere. The diffusion shell 22a comprises a pass-through 40a. The pass-through 40a is configured to allow a passage of light reflected by the illumination region 18a to a detector unit (not shown) of the image receiver 14a. The pass-through 40a is arranged on a region of the diffusion shell 22a that is maximally spaced apart from the illumination region 18a. The pass-through 40a is implemented as a recess of the diffusion shell 22a.

[0042] The diffuser element 20a comprises an envelope 48a. The envelope 48a has a cylinder-envelope-shaped basic shape. In a view starting from the illumination region 18a, the envelope 48a encompasses the diffusion shell 22a completely. The envelope 48a comprises screw threads 50a. The screw threads 50a serve for an indirect fixation of the diffuser element 20a to the image receiver 14a. Alternatively, the envelope 48a could comprise lay-in regions for nuts and/or snap elements and/or plug elements.

[0043] The diffuser unit 16a comprises an optical element 26a, which is shown in detail in FIG. 5. The optical element 26a is configured to deflect diffuse illumination light, generated from light provided by the two light sources 29a of the light source unit 12a, toward the illumination region 18a. Alternatively the optical element 26a could deflect the light provided by the two and/or from any of the six light sources 28a of the light source unit 12a toward the illumination region 18a. The optical element 26a deflects the diffuse illumination light via one-time reflection. The optical element 26a is configured to allow a passage of light reflected by the illumination region 18a, which has in particular passed the pass-through 40a. The optical element 26a comprises a semi-permeable mirror 44a. The semi-permeable mirror 44a deflects a light fraction 60a of the diffuse illumination light toward the illumination region 18a. The semi-permeable mirror 44a lets a further light fraction 62a of the diffuse illumination light pass. The optical element 26a is embodied as a beamsplitter cube. The semi-permeable mirror 44a forms a diagonal surface of the optical element 26a.

[0044] The optical element 26a comprises an absorption element 27a. The absorption element 27a is configured to absorb the further light fraction 62a. The absorption element 27a is implemented as a coating of one side of the optical element 26a.

[0045] The absorption element 27a has a refractive index that is identical to a refractive index of a remaining optical element.

[0046] The diffuser element 20a comprises a receptacle 30a. The receptacle 30a serves for a form-fit holding of the optical element 26a. The receptacle 30a is embodied as a frame. The receptacle 30a has an insertion opening that fits with the optical element 26a. The insertion opening defines an insertion direction 42a, along which the optical element 26a is insertable in the receptacle 30a. The receptacle 30a is implemented integrally with the diffusion shell 22a. Alternatively the receptacle 30a could be fastened to the diffusion shell 22a via at least one snap connection and/or plug connection and/or adhesive connection. In a view starting from the illumination region 18a, the receptacle 30a is arranged behind the pass-through 40a.

[0047] The diffuser unit 16a comprises a subregion 32a (cf. FIGS. 3 and 4). The subregion 32a is configured for feeding the light provided by the two light sources 29a into the optical element 26a. Alternatively or additionally, the subregion 32a may be configured to feed the light provided by any of the six light sources 28a into the optical element 26a; therefore just one of the light sources 28a, 29a, which may be any of the light sources 28a, 29a, will be mentioned in the following in relation to features of the subregion 32a. The subregion 32a is implemented as part of the diffuser element 20a. The subregion 32a is embodied as a planar element of the diffuser element 20a. The subregion 32a is arranged along the insertion direction 42a after the light source 28a, 29a. The subregion 32a contributes such that the light provided by the light source 28a, 29a enters the optical element 26a at least partially. The subregion 32a is additionally configured for feeding the light provided by the light source 28a, 29a at least partially into the diffusion shell 22a. In a view starting from the illumination region 18a, the subregion 32a is arranged behind the diffusion shell 22a. The subregion 32a is implemented integrally with the receptacle 30a. Alternatively, the subregion 32a could be fastened to the receptacle 30a via a snap connection and/or plug connection and/or adhesive connection. The diffuser element 20a comprises a partition wall 46a. The partition wall 46a is arranged between the subregion 32a and the receptacle 30a. The partition wall 46a is configured for converting the light provided by two of the light sources 28a and deflected by the subregion 32a into diffuse light. Alternatively the diffuser element 20a could be free of partition walls.

[0048] The diffuser unit 16a has an outer wall 34a. The outer wall 34a encompasses the diffusion shell 22a completely. The outer wall 34a comprises the envelope 48a. The outer wall 34a comprises an attachment 52a, which is shown in detail in FIG. 2. The attachment 52a is entirely implemented of an opaque material. The attachment 52a comprises an attachment receptacle 54a. The attachment receptacle 54a is configured for a form-fit holding of the image receiver 14a. The attachment receptacle 54a is implemented as an elevation of the attachment 52a. The attachment receptacle 54a has holes 56a, 57a. The holes 56a, 57a are configured to allow a passage of light provided by the light source unit 12a. The holes 56a, 57a realize a light pass-through region of the illumination device 10a. The attachment 52a has six holes 56a, which are arranged correspondingly to the six light sources 28a. The attachment 52a has two holes 57a, which are arranged correspondingly to the two light sources 29a. The two holes 57a are configured to allow a passage of light provided by the two light sources 29a to the subregion 32a. Alternatively, the attachment 52a could have any other number of holes 56a, 57a that corresponds to a number of light sources 28a, 29a of the light source unit 12a.

[0049] Alternatively or additionally, the attachment 52a may comprise a filter element (not shown). The filter element serves for a homogenization and/or scattering of a light intensity of the diffuse illumination light. The filter element could be arranged in front of the holes 56a, 57a and could, for example, reduce a light intensity of light entering through the holes 56a.

[0050] The attachment 52a comprises further screw threads 58a. Alternatively, the attachment 52a could comprise further snap elements and/or further plug elements. The further screw threads 58a correspond to the screw threads 50a for a fixation of the diffuser element 20a to the attachment 52a. In a mounted state (not shown) of the illumination device 10a, the screw threads 50a and the further screw threads 58a are respectively arranged consecutively along the insertion direction 42a. In the mounted state, the screw threads 50a and the further screw threads 58a respectively receive shared screws. The screws fix the attachment 52a and the diffuser element 20a relative to each other. In the mounted state, the illumination device 10a can be plugged as a whole onto the image receiver 14a.

[0051] The passive illumination device 10a comprises a fastening unit 36a. The fastening unit 36a is configured for a removable fixation of the diffuser unit 16a to the image receiver 14a. The fastening unit 36a is embodied as part of the diffuser unit 16a. The fastening unit 36a comprises the attachment 52a.

[0052] In FIGS. 6 and 7 two further exemplary embodiments of the invention are shown. The following descriptions are essentially limited to the differences between the exemplary embodiments, wherein regarding components, features and functions that remain the same, the description of the exemplary embodiment of FIGS. 1 to 5 may be referred to. In order to distinguish between the exemplary embodiments, the letter a in the reference numerals of the exemplary embodiment of FIGS. 1 to 5 has been replaced by the letters b and c in the reference numerals of the exemplary embodiments of FIGS. 6 and 7. In regard to components having the same denomination, in particular in regard to components having the same reference numerals, the drawings and/or the description of the exemplary embodiment of FIGS. 1 to 4 may principally be referred to.

[0053] FIG. 6 shows a diffusion shell 22b of an alternative passive illumination device 10b in a simplified isolated illustration. The diffusion shell 22b comprises an inner surface 24b, which is implemented as a partial surface of an imaginary cylinder. The inner surface 24b is implemented as a half-envelope of the imaginary cylinder.

[0054] FIG. 7 shows a diffusion shell 22c of a further alternative passive illumination device 10c in a simplified isolated illustration. The diffusion shell 22c comprises an inner surface 24c, which is embodied as a partial surface of an imaginary conus, namely as an envelope surface of an imaginary truncated conus.

TABLE-US-00001 Reference numerals 10 Beleuchtungsvorrichtung illumination device 12 Lichtquelleneinheit light source unit 14 Bildaufnehmer image receiver 16 Diffusoreinheit diffuser unit 18 Beleuchtungsbereich illumination region 20 Diffusorelement diffuser element 22 Streuschale diffusion shell 24 Innenfläche inner surface 26 optisches Element optical element 27 Absorptionselement absorption element 28 Lichtquelle light source 29 Lichtquelle light source 30 Aufnahme receptacle 32 Teilbereich subregion 34 Außenwandung outer wall 36 Befestigungseinheit fastening unit 38 System system 40 Durchlass pass-through 42 Einführrichtung insertion direction 44 halbdurchlässiger Spiegel semi-permeable mirror 46 Zwischenwand partition wall 48 Mantel envelope 50 Schraubgewinde screw thread 52 Aufsatz attachment 54 Aufsatzaufnahme attachment receptacle 56 Loch hole 57 Loch hole 58 weiteres Schraubgewinde further screw thread 60 Lichtanteil light fraction 62 weiterer Lichtanteil further light fraction