Optical distance meter having switchable receiving aperture

1. An optical distance meter comprising:

a transmitter configured to generate an oriented, transmitted beam defining a target axis,

a receiver, configured to capture at least a part of the transmitted beam returning from the target, referred to hereafter as received radiation, and

a receiving channel, which substantially defines a single capture direction for capturing the received radiation,

wherein the distance meter is configured to carry out a distance measurement by means of the transmitted beam in:

a first measuring mode, in which the distance meter is set for distance measurement on a retroreflective target, and

a second measuring mode, in which the distance meter is set for distance measurement on a diffusely scattering target,

wherein the receiving channel is configured such that, for the capture of the received radiation:

in the first measuring mode, a first aperture of the receiving channel is set, namely a first free opening of the receiving channel through which the part of the received radiation used for the distance measurement in the first measuring mode passes,

in the second measuring mode, a second aperture of the receiving channel is set, namely a second free opening of the receiving channel through which the part of the received radiation used for the distance measurement in the second measuring mode passes,

wherein the first aperture is smaller than the second aperture,

the receiving channel has a fixedly arranged attenuation element, optionally identically present in the first and second measuring mode, for attenuating the received radiation passing through the attenuation element, and

the fixedly arranged attenuation element is configured in its lateral geometry and arranged in its lateral position in the receiving channel such that:

the fixedly arranged attenuation element at least attenuates the beam bundle of the received radiation passing through the first aperture in the first measuring mode, and

in the second measuring mode, received radiation passing through the second aperture has beam bundles not attenuated by the fixedly arranged attenuation element,

the distance meter has a beam splitter arranged on the optical axis of the receiving channel for coupling the transmitted beam onto an axis which is coaxial to the optical axis of the receiving channel and corresponds to the target axis,

the beam splitter is configured and arranged such that the beam splitter has a partially-transparent layer in a central zone around the optical axis of the receiving channel, and

the partially-transparent layer forms at least a part of the fixedly arranged attenuation element.

2. The optical distance meter according to claim 1 , wherein the receiving channel has an attenuation element which is switchable in dependence on carrying out the first and second measuring mode, namely differently present in the first and second measuring mode.

3. The optical distance meter according to claim 1 , wherein the receiving channel has a switchable aperture screen defining the first aperture, wherein the switchable aperture screen is configured such that

the switchable aperture screen is pivoted into the beam path of the receiving channel in the first measuring mode, or

the screen opening of the switchable aperture screen is settable such that the first aperture is set by means of a first setting and the second aperture is set by means of a second setting.

4. The optical distance meter according to claim 3 , wherein the switchable attenuation element and the switchable aperture screen are arranged on a common adjustment element of the receiving channel and are thus jointly pivoted into the beam path of the receiving channel in the first measuring mode or jointly pivoted out of the beam path of the receiving channel in the second measuring mode, respectively.

5. The optical distance meter according to claim 1 , wherein the receiving channel has a correction optical unit defining a correction zone of the receiving channel, for compensation of a focusing error during the focusing of parts of the received radiation returning from a distance shorter than a defined close range limit distance onto the receiver, namely wherein parts of the received radiation located in the correction zone are deflected by the correction optical unit onto the receiver.

6. The optical distance meter according to claim 1 , wherein the transmitter is configured to set the transmitted beam in a defined variable focusing state, wherein:

in the first measuring mode, a first focusing state of the transmitted beam is set, wherein the transmitted beam has a divergence in the first focusing state, and

in the second measuring mode, a second focusing state of the transmitted beam is set, wherein the transmitted beam substantially has a parallel beam propagation in the second focusing state.

7. The optical distance meter according to claim 1 , wherein the transmitter is configured such that, in the first measuring mode, the transmitted beam has a defined settable beam divergence.

8. The optical distance meter according to claim 1 , wherein a transmitting channel of the optical distance meter has a switchable attenuation element.

9. The optical distance meter according to claim 1 , wherein the ratio between the area of the first aperture and the area of the second aperture is less than 1/10.

10. The optical distance meter according to claim 1 , wherein the receiving channel has an attenuation element which is switchable in dependence on carrying out the first and second measuring mode, namely differently present in the first and second measuring mode.

11. The optical distance meter according to claim 1 , wherein the switchable attenuation element and the switchable aperture screen are arranged on a common adjustment element of the receiving channel and are thus jointly pivoted into the beam path of the receiving channel in the first measuring mode or jointly pivoted out of the beam path of the receiving channel in the second measuring mode, respectively.

12. The optical distance meter according to claim 1 , wherein:

the receiving channel has a fixedly arranged attenuation element, namely identically present in the first and second measuring mode, for attenuating the received radiation passing through the attenuation element, and

the fixedly arranged attenuation element is configured in its lateral geometry and arranged in its lateral position in the receiving channel such that:

the fixedly arranged attenuation element at least attenuates the beam bundle of the received radiation passing through the first aperture in the first measuring mode, and

in the second measuring mode, received radiation passing through the second aperture has beam bundles not attenuated by the fixedly arranged attenuation element.

13. The optical distance meter according to claim 12 , wherein

the distance meter has a beam splitter arranged on the optical axis of the receiving channel for coupling the transmitted beam onto an axis which is coaxial to the optical axis of the receiving channel and corresponds to the target axis,

the beam splitter is configured and arranged such that the beam splitter has a partially-transparent layer in a central zone around the optical axis of the receiving channel, and

the partially-transparent layer forms at least a part of the fixedly arranged attenuation element.

14. The optical distance meter according to claim 1 , wherein the transmitter is configured to generate the transmitted beam having a beam divergence in the first measuring mode, and therefore:

when the distance measurement is carried out at a defined minimum measurement distance, the first aperture is completely illuminated by the received radiation, and

the beam divergence is less than five times the receiver-side field of vision angle.

15. An optical distance meter comprising:

a transmitter configured to generate an oriented, transmitted beam defining a target axis

a receiver, configured to capture at least a part of the transmitted beam returning from the target, referred to hereafter as received radiation, and

a receiving channel, which substantially defines a single capture direction for capturing the received radiation,

wherein the distance meter is configured to carry out a distance measurement by means of the transmitted beam in:

a first measuring mode, in which the distance meter is set for distance measurement on a retroreflective target, and

a second measuring mode, in which the distance meter is set for distance measurement on a diffusely scattering target,

wherein the receiving channel is configured such that, for the capture of the received radiation:

in the first measuring mode, a first aperture of the receiving channel is set, namely a first free opening of the receiving channel through which the part of the received radiation used for the distance measurement in the first measuring mode passes,

in the second measuring mode, a second aperture of the receiving channel is set, namely a second free opening of the receiving channel through which the part of the received radiation used for the distance measurement in the second measuring mode passes,

wherein the first aperture is smaller than the second aperture,

wherein the receiving channel has a switchable aperture screen defining the first aperture, wherein the switchable aperture screen is configured such that:

the switchable aperture screen is pivoted into the beam path of the receiving channel in the first measuring mode, or

the screen opening of the switchable aperture screen is settable such that the first aperture is set by means of a first setting and the second aperture is set by means of a second setting;

wherein:

the receiving channel has a fixedly arranged attenuation element, optionally identically present in the first and second measuring mode, for attenuating the received radiation passing through the attenuation element, and

the fixedly arranged attenuation element is configured in its lateral geometry and arranged in its lateral position in the receiving channel such that:

the fixedly arranged attenuation element at least attenuates the beam bundle of the received radiation passing through the first aperture in the first measuring mode, and

in the second measuring mode, received radiation passing through the second aperture has beam bundles not attenuated by the fixedly arranged attenuation element;

wherein the receiving channel has a correction optical unit defining a correction zone of the receiving channel, for compensation of a focusing error during the focusing of parts of the received radiation returning from a distance shorter than a defined close range limit distance onto the receiver, namely wherein parts of the received radiation located in the correction zone are deflected by the correction optical unit onto the receiver;

wherein the fixedly arranged attenuation element, the correction optical unit, and the switchable aperture screen are arranged in relation to one another and are each configured in the lateral geometry thereof such that:

in the first measuring mode, substantially the entire received radiation incident on the receiver is attenuated by the fixedly arranged attenuation element and is located outside the correction zone, and

in the second measuring mode, the aperture screen is pivoted out of the beam path of the receiving channel and received radiation passing through the second aperture has beam bundles not attenuated by the fixedly arranged attenuation element, which are simultaneously located inside the correction zone.

16. The optical distance meter according to claim 15 , wherein the receiving channel has an attenuation element which is switchable in dependence on carrying out the first and second measuring mode, namely differently present in the first and second measuring mode.

17. The optical distance meter according to claim 15 , wherein:

the receiving channel has a fixedly arranged attenuation element, namely identically present in the first and second measuring mode, for attenuating the received radiation passing through the attenuation element, and

the fixedly arranged attenuation element is configured in its lateral geometry and arranged in its lateral position in the receiving channel such that:

the fixedly arranged attenuation element at least attenuates the beam bundle of the received radiation passing through the first aperture in the first measuring mode, and

in the second measuring mode, received radiation passing through the second aperture has beam bundles not attenuated by the fixedly arranged attenuation element.

18. The optical distance meter according to claim 17 , wherein

the distance meter has a beam splitter arranged on the optical axis of the receiving channel for coupling the transmitted beam onto an axis which is coaxial to the optical axis of the receiving channel and corresponds to the target axis,

the beam splitter is configured and arranged such that the beam splitter has a partially-transparent layer in a central zone around the optical axis of the receiving channel, and

the partially-transparent layer forms at least a part of the fixedly arranged attenuation element.

19. The optical distance meter according to claim 15 , wherein the transmitter is configured to generate the transmitted beam having a beam divergence in the first measuring mode, and therefore:

when the distance measurement is carried out at a defined minimum measurement distance, the first aperture is completely illuminated by the received radiation, and

the beam divergence is less than five times the receiver-side field of vision angle.

20. An optical distance meter comprising:

a transmitter configured to generate an oriented, transmitted beam defining a target axis,

a receiver, configured to capture at least a part of the transmitted beam returning from the target, referred to hereafter as received radiation, and

a receiving channel, which substantially defines a single capture direction for capturing the received radiation,

wherein the distance meter is configured to carry out a distance measurement by means of the transmitted beam in:

a first measuring mode, in which the distance meter is set for distance measurement on a retroreflective target, and

a second measuring mode, in which the distance meter is set for distance measurement on a diffusely scattering target,

wherein the receiving channel is configured such that, for the capture of the received radiation:

in the first measuring mode, a first aperture of the receiving channel is set, namely a first free opening of the receiving channel through which the part of the received radiation used for the distance measurement in the first measuring mode passes,

in the second measuring mode, a second aperture of the receiving channel is set, namely a second free opening of the receiving channel through which the part of the received radiation used for the distance measurement in the second measuring mode passes,

wherein the first aperture is smaller than the second aperture,

wherein the transmitter is configured to generate the transmitted beam having a beam divergence in the first measuring mode, and therefore:

when the distance measurement is carried out at a defined minimum measurement distance, the first aperture is completely illuminated by the received radiation, and

the beam divergence is less than five times the receiver-side field of vision angle.