Patent Application
20230384214
The invention relates to an apparatus and a method for jointly detecting a color and a distance of an object.
Apparatus and methods that are configured to recognize a color or a distance of an object are known in principle. In particular when determining a color, it is desirable to also know the distance of the object since the determined color values change in dependence on the distance of the object and thus the color resolution also changes.
It is therefore an object to disclose an improved apparatus and an improved method for jointly detecting a color and a distance of an object.
This object is first satisfied by an apparatus comprising a transmission unit; a reception unit; and an evaluation unit. The transmission unit in this respect comprises a light element that is configured to emit light in a predefined wavelength range; and a transmission optics that is configured to direct the emitted light to an object. The reception unit comprises a first reception element; a second reception element that is arranged spaced apart from the first reception element; and a reception optics that is configured to receive light remitted by the object and to direct it to the first reception element and the second reception element. The evaluation unit is configured to evaluate light received by the first reception element and to determine a distance of the object and to evaluate light received by the second reception element and to determine a color of the object.
The light element is in this respect configured to emit light in a predefined wavelength range, in particular in the range of visible light. In this respect, the light element is in particular configured to emit chromatically broadband light, so-called white light.
The transmission optics directs the emitted light to an object whose color is to be recognized. One or more lenses and/or one or more mirrors can be used for this purpose.
The light is remitted by the object and is directed to a first and a second reception element by means of the reception optics that can likewise have one or more lenses and/or one or more mirrors. The first reception element is in this respect configured to return distance information and is, for example, configured as a line sensor. Alternatively, the first reception element can also be configured as a time-of-flight sensor. The second reception element is configured to return color information and is, for example, configured as a color sensor. The second reception element is in particular configured to detect different color components in the light remitted by the object, for example, by a so-called CCD sensor.
The evaluation unit then evaluates the information received from the first and second reception elements and thus determines a distance and a color.
In this respect, a single light element is in particular used to emit light that is used both for the distance detection and for the color detection. A particularly compact and favorable design of the apparatus hereby results.
One embodiment of the apparatus provides that the light element has a first light source, a second light source, and a third light source that are spaced apart from one another and that are configured to emit light in three different predefined wavelength ranges, wherein the transmission unit further has a superposition optics that is configured to superpose the light emitted by the three light sources and to direct it to a common beam axis.
The first, second, and third light source are in particular configured as semiconductor light sources, in particular light-emitting diodes. In this respect, the first, second, and third wavelength ranges in particular lie in the spectrum of visible light. The three wavelength ranges are in particular in the red, green, and blue range. The three wavelength ranges differ in this respect, but can partly overlap. This is in particular an alternative embodiment to the embodiment described further above in which the light element comprises a single light source that is configured to emit chromatically broadband light, so-called white light.
In this embodiment, the first, second, and third light source can in particular be activated after one another so that a specific emission pattern results from the three wavelength ranges. In this case, the second reception element can be configured such that it can determine, in particular only, the intensity of the remitted light and the evaluation unit determines the color of the object on the basis of this intensity, in particular taking into account the emission pattern.
A particularly good color recognition is made possible by this embodiment.
One embodiment of the apparatus provides that the superposition optics comprises a reflector that has a plurality of reflective surfaces that are arranged and configured to superpose the light emitted by the three light sources and to direct it to a common beam axis.
This embodiment of the superposition optics is, for example, described in EP 3 770 567 B1.
An alternative embodiment of the apparatus provides that the superposition optics has two dichroic mirrors that are arranged and configured to superpose the light emitted by the three light sources and to direct it to a common beam axis.
This embodiment of the superposition optics can also be designated as a beam splitter staircase.
A further alternative embodiment of the apparatus provides that the superposition optics comprises a first prism, a second prism, a third prism, and a fourth prism that are arranged adjacent to one another such that they together have a cuboid shape, wherein contact surfaces between the prisms are dichroically coated.
This embodiment in particular provides that the first, second, third, and fourth prisms are cemented and/or glued together, in particular at respective surfaces that extend from one of the legs of the triangle underlying a prism.
A particularly good superposition of the light emitted by the three light sources is made possible by these three alternative embodiments.
One embodiment of the apparatus provides that the apparatus further comprises a sectionally flexible base element at which the first light source, the second light source, and the third light source are arranged, wherein the base element is arranged around the superposition optics such that one light source each is arranged at one of three adjacent side surfaces of the superposition optics.
Due to this embodiment, a particularly simple assembly of the first, second, and third light sources is possible.
One embodiment of the apparatus provides that the base element has a first positioning element, a second positioning element, and a third positioning element that fasten the first light source, the second light source, and the third light source at a predefined distance from the three adjacent side surfaces of the superposition optics. The first, second, and third positioning elements in particular fasten the first, second, and third light sources in a width, a length, and a height in each case, i.e. in x, y, and z in space, with respect to the three adjacent side surfaces of the superposition optics.
Optionally, the first light source, the second light source, and the third light source have an aperture, wherein the predefined distance is in particular a direct contact, further in particular a gap-free contact of the respective aperture with the respective side surface of the superposition optics. Alternatively or additionally, a respective aperture can be provided between the positioning element and the respective side surface.
A particularly precise positioning of the light sources with respect to the superposition optics is ensured by this embodiment.
One embodiment of the apparatus provides that the base element further has a fourth positioning element, and wherein the first positioning element, the second positioning element, the third positioning element, and the fourth positioning element fasten the superposition optics to four adjacent side surfaces.
A particularly secure fastening of the superposition optics is made possible by this embodiment.
One embodiment of the apparatus provides that the fourth positioning element has an aperture that is configured to spatially limit the light superposed by the superposition optics.
A setting of the size and shape of the light spot on the object is made possible by this embodiment.
One embodiment of the apparatus provides that the fourth positioning element fastens the aperture at a predefined distance from the fourth side surface. The fourth positioning element in particular fastens the aperture in a width, a length, and a height, i.e. in x, y, and z in space, with respect to the fourth side surfaces of the superposition optics.
The predefined distance is in particular a direct contact, further in particular a gap-free contact.
A particularly precise superposition is made possible by this embodiment.
One embodiment of the apparatus provides that the first positioning element, the second positioning element, and the third positioning element each comprise an upper and a lower holding element that are configured to fasten the superposition optics to an upper surface and a lower surface. With the aid of these holding elements, the positioning of the first, second, and third light sources relative to the superposition optics and/or the respective aperture can in particular be ensured.
A particularly secure fastening of the superposition optics is ensured by this embodiment.
One embodiment of the apparatus provides that the evaluation unit is configured to correct the determined color based on the determined distance of the object.
For this purpose, the distance from the object is determined regularly, for example at 1 kHz, whereby a high-frequency compensation of the color values is made possible. The correction of the determined color in particular takes place based on a function that is stored in the evaluation unit and that is individually stored during the production for each color and matching the second reception element. The evaluation unit, for example, determines the distance of the object by means of triangulation based on the light spot position on the line sensor and, from this, determines compensation or correction factors for the color determined by the second reception element. This correction factor is multiplied accordingly by the signals of the second reception element to compensate the object distance in the height of the measurement signal.
On the detection of a color by the second reception element at different distances, the detected measurement signal can change by several orders of magnitude. Since the resolvability of color differences is primarily dependent on the difference of the detected measurement signal, the resolvability of color differences also changes with different object distances. To keep the color resolution as optimal as possible over the entire working zone, the electrical gain of the measurement signal of the second reception element is dynamically set depending on the height of the measurement signal and thus also on the distance of the object. Accordingly, the electrical gain is increased for large distances and low signal heights and decreased for small distances and intense signals.
The color resolution set in the evaluation unit and usable for the application is adapted in accordance with the set electrical gain and the determined distance correction factor. It can thus be adjusted in dependence on the application conditions.
A particularly precise color determination is made possible by this embodiment.
One embodiment of the invention provides that the reception optics is formed in one piece. In the present case, in one piece means made of a contiguous material and can also be referred to as integral.
A particularly compact design of the apparatus is made possible by this embodiment.
The initially mentioned object is also satisfied by a method for jointly detecting a color and a distance of an object.
In this respect, the method comprises emitting light in a predefined wavelength range; directing the emitted light to an object; receiving light remitted by the object; directing the remitted light to a first reception element and a second reception element; evaluating the light received by the first reception element to determine a distance of the object; and evaluating the light received by the second reception element to determine a color of the object.
With respect to the embodiments and advantages of the method for jointly detecting a color and a distance of an object, reference is made to the embodiments and advantages of the apparatus for jointly detecting a color and a distance of an object.
An apparatus for fastening a superposition optics is likewise provided in accordance with the invention. The apparatus comprises a sectionally flexible base element, and a first, second, and third positioning element that are arranged at the flexible base element, wherein the sectionally flexible base element is bendable such that the first positioning element can be brought into engagement with the second positioning element and the second positioning element can be brought into engagement with the third positioning element and can thus form a hollow space in which a superposition optics can be arranged. The apparatus also comprises a fourth positioning element that can be brought into engagement with the first and third positioning elements and thus fastens the superposition optics to the apparatus.
With respect to the embodiments and advantages of the apparatus for fastening a superposition optics, reference is made to the embodiments and advantages of the apparatus for jointly detecting a color and a distance of an object.
A method for fastening a superposition optics is also provided in accordance with the invention. In this respect, the method comprises the steps providing an apparatus for fastening a superposition optics comprising a sectionally flexible base element and a first, second, and third positioning element arranged thereat; bending the sectionally flexible base element; bringing the first positioning element into engagement with the second positioning element; bringing the second positioning element into engagement with the third positioning element; arranging a superposition optics within a hollow space that is formed by the engagement of the first, second, and third positioning elements; bringing a fourth positioning element into engagement with the first and third positioning elements; and thus fastening the superposition optics.
With respect to the embodiments and advantages of the method for fastening a superposition optics, reference is made to the embodiments and advantages of the apparatus for fastening a superposition optics.
Embodiments of the apparatus and the method for jointly detecting a color and a distance of an object and of the apparatus and the method for fastening a superposition optics are now described in more detail in connection with the following Figures. There are shown:
In this respect, identical reference numerals refer to identical or similar features.
The apparatus 10 has a transmission unit 100, a reception unit 200, and an evaluation unit that is not shown for reasons of clarity.
The transmission unit 100 comprises a light element 110. In this respect, the light element 110 comprises a first light source 111, a second light source 112, and a third light source 113 that are each spaced apart from the other. The first light source 111 is in this respect configured to emit light in a first predefined wavelength range, the second light source 112 is configured to emit light in a second predefined wavelength range, and the third light source 112 is configured to emit light in a third predefined wavelength range. The first wavelength range, the second wavelength range, and the third wavelength range are different in this respect, but can partly overlap.
The transmission unit 100 also comprises a superposition optics that is configured to superpose the light emitted by the three light sources 111, 112, 113 and to direct it to a common beam axis. In this respect, the superposition optics is here shown by way of example as a beam superposition cube 115. The beam superposition cube consists of four prisms that are fastened to one another and that are dichroically coated with one another on the contact surfaces. The beam superposition cube in this respect has four rectangular side surfaces that are of the same size and that are arranged in a rectangular manner with respect to one another as well as a rectangular roof surface and a floor surface that are likewise arranged at right angles to the side surfaces and that either have the same size as the side surfaces or a different size. In the present case, the term cube thus also includes cuboids.
In this respect, the three light sources 111, 112, 113 are arranged around the sides of the beam superposition cube 115 such that a beam direction of the light emitted by the first light source 111 is offset by 90 degrees in the drawing plane from a beam direction of the light emitted by the second light source 112 and a beam direction of the light emitted by the second light source 112 is offset by 90 degrees in the drawing plane from a beam direction of the light emitted by the third light source 113, i.e. the first light source 111 and the third light source 113 are opposed to one another by 180 degrees in the drawing plane. In this respect, the beam superposition cube 115 is arranged and configured in such a manner to direct and to superpose the three beam directions of the three light sources such that a common light beam is emitted opposite to the second light source 112 from the beam superposition cube 115.
The apparatus 10 can in particular also have an apparatus for fastening a superposition optics that is described in more detail in the following
Other embodiments of a superposition optics, such as a reflector that has a plurality of reflective surfaces or two dichroic mirrors that are likewise configured to superpose the light emitted by the three light sources and to direct it to a common beam axis, which is, however, not shown in the Figures, are equally possible.
The transmission unit 100 also comprises a deflection optics 120 that is configured to deflect the light emitted by the three light sources 111, 112, 113 and superposed by the superposition optics and to redirect it to a transmission optics 130. The transmission optics is in this respect configured to direct the light emitted by the three light sources 111, 112, 113 to an object. The object is not shown for reasons of clarity and is in this respect located to the right of the apparatus 10, outside the drawing area.
The apparatus 10 also comprises a front lens 250 through which the light emitted by the three light sources 111, 112, 113 exits the apparatus, which is shown by the optical path 1. The emitted light is then remitted at the object, which is shown by the optical path 2, and re-enters the apparatus 10 as remitted light through the front lens 250.
There, the remitted light is incident on a reception optics 230 of the reception unit 200 that directs the remitted light to a first reception element 210, on the one hand, and to a second reception element 220, on the other hand, that is spaced apart from the first reception element 210. The first reception element 210 and the second reception element 220 are in this respect configured to receive the light directed to them and to convert it into an electrical signal.
The evaluation unit, not shown, is in this respect configured to evaluate the light received by the first reception element 210 or the electrical signal formed from said light and to determine a distance of the object. The evaluation unit is also configured to evaluate the light received by the second reception element 220 or the electrical signal formed from said light and to determine a color of the object.
Both the transmission unit 100 with all its described components and the reception unit 200 with all its described components are in this respect accommodated in a single housing, not shown for reasons of clarity, that has the front lens 250 as its only optical interface. The evaluation unit can be located either in the housing or outside thereof. The apparatus 10 for jointly detecting a color and a distance of an object in particular uses a single light element 110 comprising three light sources, in particular exactly three light sources, that are used both to determine a color and to determine a distance of the object.
As initially shown in
A first positioning element 320 is arranged at the first rigid section 311, a second positioning element 330 is arranged at the second rigid section 312, and a third positioning element 340 is arranged at the third rigid section 313.
In this respect, the first positioning element 320, the second positioning element 330, and the third positioning element 340 are substantially uniform in shape, wherein each of the positioning elements has a plurality of holding elements and a plurality of locking elements that will be described in the following.
The first positioning element 320 has an upper holding element 321, a lower holding element 324, and four lateral locking elements 322, 323, 325, and 326. Equally, the second positioning element 330 has an upper holding element 331, a lower holding element 334, and four lateral locking elements 332, 333, 335, and 336. The third positioning element 340 also has an upper holding element 341, a lower holding element 344, and four lateral locking elements 342, 343, 345, and 346. In this respect, the two left lateral locking elements 322 and 323, 332 and 333, and 342 and 343 are each arranged offset outwardly from the respective corresponding two right lateral locking elements 325 and 326, 335 and 336, and 345 and 346.
In this respect, the locking elements are arranged such that they can engage with corresponding grooves in the respective adjacent positioning element and can thus fasten the positioning elements to one another.
A light source is centrally arranged in each of the three positioning elements 320, 330, 340, wherein only the first light source 111 in the first positioning element 320 is provided with a reference numeral. Each of the three light sources is in this respect provided with an aperture that is likewise not shown for reasons of clarity.
In this respect, the first positioning element 320, the second positioning element 330, and the third positioning element 340 are fastened to the sectionally flexible base element 310 in the SMD process.
A first flexible section is arranged between the first rigid section 311 and the second rigid section 312 and a second flexible section is arranged between the second rigid section 312 and the third rigid section 313, wherein the rigid sections 315 and 316 are not provided with a reference numeral for reasons of clarity. The base element 310 can also have further flexible sections that are not provided in detail here with reference numerals.
The fourth rigid section 314 furthermore has fastening and/or connection elements for fastening and/or connecting the apparatus 300 to a housing of an apparatus 10 for jointly detecting a color and a distance of an object, as shown in
As can be seen in
Around the beam superposition cube 115, in this method step shown in this
As can likewise be seen in this
Equally, it can be seen in
The first light source 111, the second light source 112, and the third light source 113 can also be seen in
As can be seen from
Equally, it can be seen in
In this
In this respect, the apparatus 300 is introduced into a fastening sleeve 400. The fastening sleeve 400 comprises an upper surface 410, a lower surface 450, and three side surfaces 420, 430, and 440. A fourth side surface is not provided. The apparatus can thus be particularly easily introduced into the fastening sleeve 400.
In this respect, the left and right side surfaces 420 and 440 comprise a fastening element of which only that one of the left side surface is provided with a reference numeral 422. The upper surface 410 and the lower surface 450 each also comprise fastening elements 411 and 451. These fastening elements serve to fasten the apparatus 300 in a housing.
In this respect, the fastening element 442 of the right side surface is in particular also visible.
In this respect, the method 1000 comprises, in a first step 1010, emitting light in a predefined wavelength range. This step can in particular take place by the light element 110 shown in
In a further step 1020, the method 1000 comprises directing the emitted light to an object. This can in particular take place with the aid of the transmission optics 130 shown in
In a further step 1030, the method 1000 comprises receiving light that is remitted by the object.
In a further step 1040, the method 1000 comprises directing the remitted light to a first reception element and a second reception element. This can in particular be a first reception element 210 and a second reception element 220, as shown in
In a further step 1050, the method 1000 comprises evaluating the light received by the first reception element to determine a distance of the object.
In a further step 1060, the method 1000 comprises evaluating the light received by the second reception element to determine a color of the object.
The method steps described, in particular steps 1050 and 1060, can in this respect be carried out simultaneously.
In a further step, which is not shown in
In a first step 1310, an apparatus for fastening a superposition optics is provided, comprising a sectionally flexible base element and a first, second, and third positioning element arranged thereat, in particular an apparatus for fastening a superposition optics as shown in
In a following step 1320, the sectionally flexible base element is bent and the first positioning element is brought into engagement with the second positioning element and the second positioning element is brought into engagement with the third positioning element.
In a further step 1330, a superposition optics is provided.
In a further step 1340, the superposition optics is arranged within a hollow space that is created by the engagement of the first, second, and third positioning elements, in particular as shown in
In a further step 1350, a fourth positioning element is provided.
In a subsequent step 1360, the fourth positioning element is brought into engagement with the first and third positioning elements and thus fastens the superposition optics, in particular as shown in
In a further step 1370, a fastening sleeve is provided.
In a subsequent step 1380, the fastening sleeve is fastened to the sectionally flexible base element, as shown in
In an optional step, not shown, the fastening sleeve can be fastened to a housing, in particular to a housing of an apparatus for jointly detecting a color and a distance of an object, as shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 22175219.9 | May 2022 | EP | regional |
