Abstract
A device comprising an electrical circuit on a substrate. The circuit includes light-emitting semiconductor components having a plurality of a first type and at least one of a further type, and a first plurality of parallel circuit paths. Each first type component emits light with a spectrum comprising a local intensity maximum in a first wavelength range; each further type component, in a further wavelength range different from the first wavelength range. At least one of the parallel circuit paths comprises a further type component. No operating voltage sum of the parallel circuit paths differs by more than 0.6 V from an operating voltage sum of the parallel circuit paths. Also disclosed are a light source; a printing machine; methods, in particular for producing a printed product and for irradiating an irradiation material; a printed product; an arrangement; and uses of the light source.
Claims
1. A device comprising: a substrate; and an electrical circuit arranged on the substrate and having a first section with (i) a first plurality of light-emitting semiconductor components including a plurality of light-emitting semiconductor components of a first type and at least one light-emitting semiconductor component of a further type, and (ii) a first plurality of parallel circuit paths connected in parallel with each of the parallel circuit paths of the first plurality of parallel circuit paths having a first end and an oppositely positioned further end, wherein the first ends of the parallel circuit paths of the first plurality of parallel circuit paths are electro-conductively connected to each other and the further ends of the parallel circuit paths of the first plurality of parallel circuit paths are electro-conductively connected to each other; wherein each light-emitting semiconductor component of the first type is arranged and adapted to emit light with a spectrum comprising a local intensity maximum in a first wavelength range upon application of an operating voltage of the light-emitting semiconductor component of the first type; wherein each light-emitting semiconductor component of the further type is arranged and adapted to emit light with a spectrum comprising a local intensity maximum in a further wavelength range, different from the first wavelength range, upon application of an operating voltage of the light-emitting semiconductor component of the further type; wherein at least one of the parallel circuit paths of the first plurality of parallel circuit paths comprises a light-emitting semiconductor component of the further type; wherein each parallel circuit path of the first plurality of parallel circuit paths has an operating voltage sum, which is a sum of the operating voltages of the light-emitting semiconductor components in the respective parallel circuit path; and wherein no operating voltage sum of the parallel circuit paths of the first plurality of parallel circuit paths differs by more than 0.6 V from an operating voltage sum of the parallel circuit paths of the first plurality of parallel circuit paths.
2. The device according to claim 1, wherein the first wavelength range is from 315 to 450 nm; or the further wavelength range is from 280 to less than 315 nm, or from 10 to less than 280 nm, or both; or the first wavelength range is from 315 to 450 nm and the further wavelength range is from 280 to less than 315 nm, or from 10 to less than 280 nm, or both.
3. The device according to claim 1 wherein the light-emitting semiconductor components of the first type have first operating voltages and the light-emitting semiconductor components of the further type have further operating voltages different from the first operating voltages.
4. The device according to claim 1 wherein no light-emitting semiconductor component of a parallel circuit path of the first plurality of parallel circuit paths is connected in series with a light-emitting semiconductor component of a different parallel circuit path of the first plurality of parallel circuit paths.
5. The device according to claim 1 wherein the electrical circuit has a first double-T-shaped conductive track including a first transverse bar, a further transverse bar, and a longitudinal bar electrically connecting the first transverse bar with the further transverse bar.
6. The device according to claim 1 wherein the light-emitting semiconductor components of the first type are UV-A light-emitting diodes.
7. The device according to claim 1 wherein the light-emitting semiconductor components of the further type are UV-B light-emitting diodes or UV-C light-emitting diodes or a mixture of UV-B light-emitting diodes and UV-C light-emitting diodes.
8. The device according to claim 1 wherein the light-emitting semiconductor components of the first plurality of light-emitting semiconductor components are UV light-emitting diodes.
9. A light source comprising the device according to claim 1.
10. A printing machine comprising a light source including the device according to claim 1.
11. A method comprising the steps of: providing an item and a light source including the device according to claim 1; superimposing the item with a composition; and irradiating the composition with light emitted from at least a portion of the light-emitting semiconductor components of the first plurality of light-emitting semiconductor components.
12. The method according to claim 11 wherein the step of irradiating the composition includes curing the composition.
13. A printed product obtained by the method according to claim 11.
14. A printed product obtained by the method according to claim 12.
15. An arrangement comprising: a light source including the device according to claim 1; and an irradiation material, wherein the light source and the irradiation material are arranged and adapted for irradiating the irradiation material with light emitted from at least a portion of the light-emitting semiconductor components of the first plurality of light-emitting semiconductor components.
16. A method comprising the steps of: providing an arrangement having a light source including the device according to claim 1 and an irradiation material, wherein the light source and the irradiation material are arranged and adapted for irradiating the irradiation material with light emitted from at least a portion of the light-emitting semiconductor components of the first plurality of light-emitting semi-conductor components; and irradiating the irradiation material with light emitted from at least a portion of the light-emitting semiconductor components of the first plurality of light-emitting semiconductor components.
17. A use of a light source including the device according to claim 1 in a printing machine.
18. A use of a light source including the device according to claim 1 to cure a composition.
Description
BRIEF DESCRIPTION OF THE DRAWING
[0143] The invention is described in more detail below by examples and drawings, wherein the examples and drawings do not constitute a limitation of the invention. Furthermore, the drawings are not to scale, unless otherwise indicated.
[0144] Unless otherwise indicated in the description or the respective figure, they are schematic and not to scale:
[0145] FIG. 1 is a schematic representation of a device according to the invention;
[0146] FIG. 2 is a schematic representation of a further device according to the invention;
[0147] FIG. 3a) is a schematic representation of a further device according to the invention;
[0148] FIG. 3b) is a schematic representation of a further device according to the invention of circuit paths of the electrical circuit of the device according to the invention of FIG. 3a);
[0149] FIG. 4 is a schematic representation of a light source according to the invention;
[0150] FIG. 5 is a schematic representation of a printing machine according to the invention;
[0151] FIG. 6 is a flowchart of a method according to the invention for producing a printed product;
[0152] FIG. 7 is a schematic representation of a printed product according to the invention;
[0153] FIG. 8 is a schematic representation of an arrangement according to the invention; and
[0154] FIG. 9 a flow chart of a method according to the invention for irradiating an irradiation material.
DETAILED DESCRIPTION OF THE DISCLOSURE
[0155] FIG. 1 shows a schematic representation of a device 100, which comprises a substrate 101 of aluminum oxide. On the substrate 101 is an electrical circuit 102 of conductive tracks 109, electrical contacts 108 for connecting a voltage source, and a first plurality of light-emitting semiconductor components. The first plurality of light-emitting semiconductor components consists in the illustrated embodiment of two light-emitting semiconductor components of a first type 103 and one light-emitting semiconductor component of a further type 104. The light-emitting semiconductor components of the first type 103 are arranged and adapted to emit light with a spectrum comprising a local intensity maximum in a first wavelength range when an operating voltage of the light-emitting semiconductor components of the first type 103 is applied. In contrast thereto, the light-emitting semiconductor component of the further type 104 is arranged and adapted to emit light with a spectrum comprising a local intensity maximum in a further wavelength range, different from the first wavelength range, when an operating voltage of the light-emitting semiconductor component of the further type 104 is applied. The conductive tracks 109 and the light-emitting semiconductor components of the first plurality are arranged in such a manner that the electrical circuit 102 comprises two parallel circuit paths 105 connected in parallel to each other. Each of these parallel circuit paths 105 has a first end 106 and a further end 107 opposite its first end 106. The first ends 106 of the two parallel circuit paths 105 are electro-conductively connected to each other by one of the conductive tracks 109. In addition, the further ends 107 of the two parallel circuit paths 105 are electro-conductively connected to each other by another of the conductive tracks 109. The two light-emitting semiconductor components of the first type 103 are arranged together in one of the two parallel circuit paths 105. The light-emitting semiconductor component of the further type 104 is arranged in the other parallel circuit path 105. Each of the two parallel circuit paths 105 is characterized by a sum of operating voltages, which is a sum of the operating voltages of the light-emitting semiconductor components in the respective parallel circuit path 105. The two operating voltage sums differ in this embodiment by no more than 0.3 V.
[0156] FIG. 2 shows a schematic representation of a further device 100 according to the invention, which in turn comprises a substrate 101 made of a ceramic material such as aluminum nitride. The substrate 101 is a planar circuit board with flat surfaces. An electrical circuit 102 is directly applied to one of these flat surfaces. This electrical circuit 102 comprises electrical contacts 108 for connecting a voltage source, printed conductive tracks 109, and light-emitting semiconductor components, which are UV-LEDs. The electrical circuit 102 consists of a first section 201 and a further section 202, which are identical except for the mirror-inverted assembly of the electrical contacts 108 and a conductive track 109 electro-conductively connecting the two sections 201, 202. Of the light-emitting semiconductor components of the device 100, the first section 201 comprises a first plurality of the light-emitting semiconductor components and the further section 202 comprises a further plurality of the light-emitting semiconductor components. The first plurality of light-emitting semiconductor components consists of six light-emitting semiconductor components of a first type 103 and two light-emitting semiconductor components of a further type 104. Consequently, the further plurality of light-emitting semiconductor components also consists of six light-emitting semiconductor components of the first type 203 and two light-emitting semiconductor components of the further type 204. The light-emitting semiconductor components of the first type 103, 203 are UV-A LEDs with an intensity maximum of their emission spectrum at 365 nm. The UV-A LEDs are of a binning class, which defines an operating voltage in a range of 3.3 to 3.4 V. The light-emitting semiconductor components of the further types 104, 204 are UV-C LEDs with an intensity maximum of their emission spectrum at 250 nm. Further, a binning class of UV-C LEDs defines an operating voltage in a range of 6.7 to 6.8 V. Still further, each UV-LED of the device 100 is characterized by a forward direction 208. This is represented in FIG. 2 by an arrow. The first section 201 and the further section 202 of the electrical circuit 102 each comprise five parallel circuit paths 105 and 205, respectively, connected in parallel. Each parallel circuit path 105 of the first section 201 has a first end 106 and a further end 107 opposite its first end 106 in the forward direction 208. Each parallel circuit path 205 of the further section 202 also has a first end 206 and a further end 207 opposite its first end 206 in the forward direction 208. The first ends 106 of the parallel circuit paths 105 of the first section 201 are electro-conductively connected to each other by one of the conductive tracks 109. In addition, the further ends 107 of the five parallel circuit paths 105 of the first section 201 are electro-conductively connected to each other by another of the conductive tracks 109. The same applies analogously to the first ends 206 and the further ends 207 of the parallel circuit paths 205 of the further section 202. Each of the parallel circuit paths 105, 205 is characterized by a sum of operating voltages, which is a sum of the operating voltages of the UV LED in the respective parallel circuit path 105, 205. The operating voltage sums of the parallel circuit paths 105 of the first section 201 do not differ from each other by more than 0.2 V. The same applies to the operating voltage sums of the parallel circuit paths 205 of the further section 202. This allows, in particular, the joint operation of the UV-A LED and the UV-C LED in the electrical circuit 102 on the substrate 101 which is formed as one piece. This enables an emission spectrum specifically adapted to a certain UV-curable ink, and at the same time stripes and steps in an intensity distribution on an irradiation surface can be avoided. Furthermore, none of the UV LEDs of a parallel circuit path 105 of the first section 201 is connected in series with a UV LED of a different parallel circuit path 105 of the first section 201. Similarly, none of the UV LEDs of a parallel circuit path 205 of the further section 202 is connected in series with a UV LED of a different parallel circuit path 205 of the further section 202. This reduces the susceptibility of the device 100 to failure, especially in the event of a failure of a single UV LED. If a single UV-LED fails, the number of UV-LEDs that are forced to fail is limited. As a result, the device 100 often does not have to be maintained or replaced if a single UV LED fails, but can still be operated. This increases the service life of the device 100.
[0157] FIG. 3a) shows a schematic representation of a further device 100 according to the invention. A substrate 101 of the device 100 consists of aluminum oxide. The substrate 101 is a planar circuit board with flat surfaces formed as one piece. An electrical circuit 102 is directly applied to one of these flat surfaces. This electrical circuit 102 comprises electrical contacts 108 for connecting a voltage source, conductive tracks 109 and light-emitting semiconductor components, which are UV LEDs. The electric circuit 102 consists of a first section 201 and four further sections 202. Of the light-emitting semiconductor components of the device 100, the first section 201 comprises a first plurality of light-emitting semiconductor components, and each of the further sections 202 comprises a further plurality of light-emitting semiconductor components. The first plurality of light-emitting semiconductor components consists of eight light-emitting semiconductor components of a first type 103 and three light-emitting semiconductor components of a further type 104. Furthermore, each further plurality of light-emitting semiconductor components also consists of eight light-emitting semiconductor components of the first type 203 and three light-emitting semiconductor components of the further type 204. The light-emitting semiconductor components of the first type 103, 203 are UV-A LEDs each with an operating voltage of about 3.3 V. The light-emitting semiconductor components of the further type 104, 204 are UV-C LEDs each with an operating voltage of about 6.6 V each. Furthermore, each UV LED of the device 100 is characterized by a forward direction 208. This is represented in FIG. 3a) by an arrow. The conductive tracks 109 of the electrical circuit 102 comprise five double-T-shaped conductive tracks. Each of these double-T-shaped conductive tracks consists of a first transverse bar 301 or 304, a further transverse bar 303 or 306, and a longitudinal bar 302 or 305 electrically connecting the first transverse bar to the further transverse bar. The first transverse bar, the longitudinal bar and the further transverse bar of each double-T-shaped conductive track are adjacent to each other in this order in the forward direction 208. Further conductive tracks 109 of the device 100 are bonding wires 307. The first section 201 of the electrical circuit 102 comprises seven parallel circuit paths 105 connected in parallel to one another (see FIG. 3b)). Each further section 202 of the electrical circuit 102 also comprises seven parallel circuit paths 205 connected in parallel to one another (see FIG. 3b)). Each parallel circuit path 105 of the first section 201 has a first end 106 and a further end 107 opposite its first end 106 in the forward direction 208. Each parallel circuit path 205 of each further section 202 also has a first end 206 and a further end 207 opposite its first end 206 in the forward direction 208. The first ends 106 of each parallel circuit path 105 of the first section 201 are electro-conductively connected to each other by the first transverse bar 301 of a first double-T-shaped conductive track. Furthermore, the further ends 107 of the seven parallel circuit paths 105 of the first section 201 are electro-conductively connected to each other by the first transverse bar 304 of a further double-T-shaped conductive track. Similarly, the first ends 206 and the further ends 207 of the parallel circuit paths 205 of each further section 202 are connected to each other by a first transverse bar 304 of a further double-T-shaped conductive track. In each of the sections 201, 202, two of the total of eight UV-A-LEDs are arranged together in one of the seven parallel circuit paths 105, 205 while one of the total of three UV-C-LEDs is arranged in one of the other seven parallel circuit paths 105, 205. The eight UV-A LEDs of a section 201, 202 each comprise two UV-A LEDs of the same emission spectrum, wherein the emission spectra of the UV-A LEDs otherwise differ from each other. Two of the eight UV-A LEDs of a section 201, 202 have an emission spectrum with a local intensity maximum at 365 nm, two other UV-A LEDs have an emission spectrum with a local intensity maximum at 385 nm, two other UV-A LEDs have an emission spectrum with a local intensity maximum at 395 nm, and two UV-A LEDs have an emission spectrum with a local intensity maximum at 405 nm. In each case two UV-A LEDs with the same emission spectrum are arranged together in a parallel circuit path 105, 205. The three UV-C LEDs of each section 201, 202 are distributed such that one UV-C LED is in each of the three remaining parallel circuit paths 105, 205 of the section 201, 202. These three remaining parallel circuit paths 105, 205 of each section 201, 202 overlap each other in a longitudinal bar 302, 305 of a double-T-shaped conductive track. Each of the parallel circuit paths 105, 205 is characterized by a sum of operating voltages, which is a sum of the operating voltages of the UV LED in the respective parallel circuit path 105, 205. It follows that the operating voltage sums of the parallel circuit paths 105 of the first section 201 do not differ from each other by more than 0.1 V. The same applies to the operating voltage sums of the parallel circuit paths 205 of each further section 202. The assembly of UV-A LED and UV-C LED described above allows a total emission spectrum of a light source 400 to be modified very flexibly and easily for different UV-curable printing inks or lacquers to be irradiated with a device 100. Furthermore, none of the UV LEDs of a parallel circuit path 105 of the first section 201 is connected in series with a UV LED of a different parallel circuit path 105 of the first section 201. Similarly, none of the UV LEDs of a parallel circuit path 205 of a further section 202 is connected in series with a UV LED of a different parallel circuit path 205 of the same further section 202. This reduces the susceptibility to failure of a light source 400 with the device 100. The UV-C LEDs of the first section 201 are electro-conductively connected to the longitudinal bar 302 and the further transverse bar 303 of the first double-T-shaped conductive track by bonding wires 307. Furthermore, the first transverse bar 301 of the first double-T-shaped conductive track is electro-conductively connected along each of the parallel circuit paths 105 of the first section 201 by bonding wires 307 to the first transverse bar 304 of the further double-T-shaped conductive track in a following manner and in the forward direction 208. In addition, the further transverse bar 303 of the first double-T-shaped conductive track is electro-conductively connected along each parallel circuit path 105 of the four parallel circuit paths 105 of the first section 201 equipped with UV-A LEDs by bonding wires 307 to the first transverse bar 304 of the further double-T-shaped conductive track in a following manner and in the forward direction 208. The double-T-shaped conductive tracks are screen-printed conductive tracks. The above described combination of bonding wires 307 and printed conductive tracks in the described assembly of the electrical circuit 102 makes it possible to manufacture the device 100 simply and efficiently, and also allows a light source 400 with the device 100 to be made in a particularly compact manner.
[0158] FIG. 3b) shows a schematic representation of circuit paths of the electrical circuit 102 of the device 100 according to the invention. In comparison with FIG. 3a), it can be seen that the electrical circuit 102 comprises seven parallel circuit paths 105 in the first section 201 and seven parallel circuit paths 205 in each further section 202.
[0159] FIG. 4 shows a schematic representation of a light source 400 according to the invention. This light source 400 is a UV luminaire of the UV4000 Semray class from Heraeus Noblelight GmbH, which was retrofitted with a device 100 according to the invention, and according to the structure shown in FIG. 3a), as an LED package. The device 100 is partially surrounded by a housing 401 of the device 100. Furthermore, the light source 400 comprises an emission window 402 made of quartz glass, which is arranged on one side of the substrate 101 facing the electrical circuit 102 of the device 100. The light source 400 further comprises connections 403 for an inflow and an outflow of a cooling fluid for cooling the device 100.
[0160] FIG. 5 shows a schematic representation of a printing machine 501 according to the invention. The printing machine 501 comprises the light source 400 of FIG. 4. The light source 400 is arranged in the printing machine 501 to irradiate a composition printed on a print carrier 502. The printing machine 501 is a sheet-fed offset printing machine.
[0161] FIG. 6 shows a flow chart of a method 600 according to the invention for the production of a printed product 700 (see FIG. 7). In the first method step 601, the printing machine 501 of FIG. 5 and a print carrier 802 are provided as an item (see FIG. 8). In a subsequent method step 602, a liquid composition 803, which is a sheet-fed offset printing ink, is printed on the print carrier 802 with the printing machine 501. In a third method step 603, the printed sheet-fed offset printing ink is simultaneously irradiated with UV light 804, emitted by UV-A LEDs with different emission spectra and by UV-C LEDs of the light source 400, and is thereby cured by polymerization. The intensity distribution of the UV light 804 produced in the method step 603 on the print carrier 802 or the sheet-fed offset printing ink is very homogeneous and, in particular, does not show any stripes or steps. In addition, a total spectrum of the UV light 804 is adjusted to the sheet-fed offset printing ink. This means that the sheet-fed offset printing ink can be cured very efficiently and evenly across the print carrier 802.
[0162] FIG. 7 shows a schematic representation of a printed product 700 according to the invention. As illustrated in this embodiment, the printed product 700 is a brochure obtained by the method 600 of FIG. 8.
[0163] FIG. 8 shows a schematic representation of an arrangement 800 according to the invention. The arrangement 800 comprises the printing machine 501 of FIG. 5 and an irradiation material 801, which consists of an item including a print carrier 802 and a printing ink 803 printed on the print carrier 802. The light source 400 of the printing machine 501 and the irradiation material 801 are arranged such that the printed printing ink 803 can be irradiated with the UV light 804 emitted by the UV LED of the light source 400.
[0164] FIG. 9 shows a flowchart of a method 900 according to the invention for irradiating an irradiation material 801. In a first method step 901, the arrangement 800 of FIG. 8 is provided. In a second method step 902, the irradiation material 801 is irradiated simultaneously with the UV light 804, emitted by UV-A LEDs of different emission spectra and by UV-C LEDs of the light source 400.
[0165] Although illustrated and described above with reference to certain specific embodiments and examples, the present disclosure is nevertheless not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the spirit of the disclosure.
