DE202008013691U1 - Electro-optical measuring device - Google Patents

Abstract

Electro-optical Measuring device (1), in particular hand-held and non-contact Distance measurement, with an optical transmission path (20), at least an optical transmitter (21) for emitting optical measuring beams (24), and with a reception path (25) with at least one Receiving optics (27) for the bundling of reflected measuring beams towards a receiver (26), as well as with a component of transmitting and receiving path receiving, in particular in one piece trained optics carrier body (10), characterized characterized in that the optical carrier body (10) made of thixomolding shaped light metal.

Description

The The invention relates to an electro-optical measuring device according to the preamble of claim 1.

Electro-optical Measuring devices that have an optical transmission path with at least an optical transmitter and an optical receiving path with at least have a receiving optics require an increased level of mechanical and thermal stability to ensure that the optical axes of, for example, send and receive path in a once adjusted manner to each other.

From the DE 19804050 A1 a device for optical distance measurement is known, in which the transmitting device, the receiving optics and a transducer for the measuring signal form a common structural unit, which are integrated in a housing of the distance measuring device. The assembly comprises a carrier body made of die-cast zinc. The carrier body of the measuring device of DE 19804050 A1 is predominantly plate-shaped and has on a side facing the object to be measured on a frame which is supported by two lateral ribs on the frame body. The exit channel of the optical device of this distance measuring device is fixedly mounted on the carrier body. For this purpose, tabs are integrally formed on the outlet channel, via which the outlet channel can be screwed by means of screws to the carrier body. The outlet channel, which is made of plastic, forms on its outer wall a receptacle for an electro-optical converter.

From the DE 10157378 A1 a measuring device for non-contact distance measurement is known, which has an optical transmission path with an optical transmitter and an optical receiving path with a receiver optical system and an optical receiver and a component of these receiving and receiving module receiving device module. To maintain high measurement accuracy over the entire temperature range, the components of the transmit and receive paths are positioned such that, given a temperature-related curvature of the device module in the direction of the optical axes of the transmit and receive paths, the optical axes are deflected by the same amount in the same direction ,

In the published patent application WO 2007/028667 describes a hand-held electro-optical measuring device for distance measurement, which has a transmission path with an optical transmitter and a receiving path with at least one receiving optical system for focusing a measurement signal in the direction of a receiver. Furthermore, the electro-optical measuring device has an optical carrier body, which accommodates components of the transmitting and receiving paths and consists of plastic.

When disadvantageous, however, proves that the plastic existing optics carrier body become porous can as well as - for example, in a hard impact after a fall - can deform or even break.

Of Further have optical carrier body made of plastic a high coefficient of thermal expansion, usually only by additional fillers, such. Glass fibers, Carbon fibers or mineral fibers, can be reduced. These fillers lead to asymmetrical shrinkage and expansion coefficients which is extremely negative for the transmitter-receiver stability effect.

As well A design of the optical carrier body is known made of metal. However, this is often a machining post-processing the die-cast parts necessary to make this with the produce required dimensional accuracy. When die casting arise, due to a turbulent flow during filling of the part, Innhomogenitäten - also called Lunker -, which adversely affects the transmitter-receiver stability can affect. In addition, die castings, as used in devices of the prior art, a shiny metallic surface, resulting in the Usually a surface coating to avoid secondary reflections, for example, between a receiving lens and the actual Receiver, necessary. Also, such die castings usually very heavy, so they are for hand-held gauges less suitable.

Of the Invention is therefore the object of an improved electro-optical To provide the measuring device.

A Another object of the invention is to provide a more stable and more durable, yet lightweight and inexpensive to be manufactured optical carrier body, this especially for use in a hand-held Laser rangefinder is suitable.

These Task is achieved by the realization of the characterizing features of the independent claim. Features that further develop the invention in an alternative or advantageous manner, can be found in the dependent claims.

The electro-optical measuring device according to the invention has an optical transmission path with at least one optical transmitter for the transmission of a measuring signal and a receiving path with at least one receiving optical system for focusing a measuring signal in the direction of a receiver. Furthermore, the electro-optical measuring device has an optical carrier body which receives components of the transmit and receive paths. The optics carrier body of the electro-optical measuring device is formed according to the invention in light metal formed by thixomolding, wherein thixomolding is also known by the terms thixoforming, thixotropic, thixocasting or semi-solid metal casting.

Especially the optics carrier body may consist of a magnesium or aluminum alloy.

Of the Optics carrier body can in all nach Forms known in the art and in particular in one piece be trained so that he is responsible for wearing components of Send and receive path is suitable.

Especially has to the optics carrier body a recording for the optical transmitter, for example a laser diode, and a recording for an exit window for the transmission beams, with a cylindrical in between Transmitting channel in which the transmitted beams extend, can be shaped. Furthermore, between a recording for the Receiving optics, such as a receiving lens, and the receiver a tube be formed, in particular parallel to the transmission channel is arranged.

The Training the optics carrier body in means of Thixomolding formed light metal, in particular magnesium or Aluminum, allows the production of such, having fine structures having carrier body lower tolerances, so that a post-machining, often known in the art, urgeformten by die casting Metal-optic supports required may be omitted. In addition, according to the invention according to the thixomolding principle manufactured optics carrier body a higher Rigidity, stability and temperature resistance and a lower porosity than comparable plastic body and also as comparable metallic die castings.

These Properties can be due to the laminar flow Refill filling of the part. By This laminar flow makes it possible to a very exact impression of the part and especially of the surface structures to achieve. These exactly reproducible surface structures can be used for diffuse reflections, contrary to surfaces of bodies, which are produced by die casting is not the case.

The allow high stability and good aging properties a long-lasting stable and fixed position fixing of the optical Components on the optical carrier body, whereby the Measurements even after many years and rough use of the Meter still reach the required accuracy. Likewise, the metal formed by thixomolding is most pronounced temperature resistant, so that the pre-aligned position of the optical Components to each other even in strongly fluctuating temperatures remains constant and the measurements are not affected.

Of Further, the optical carrier body produced by thixomolding a matt, diffusely reflective, bright and resistant Surface on, so on shiny one Metal-optic carriers otherwise usual plastic coating to avoid secondary reflections, for example between a receiving lens and the actual receiver, can be waived. The inventively shaped Optics carrier body has such a surface on, that such reflections are avoided from the outset can.

In As is known, with the thixo-molding molded optical carrier body, especially in such a magnesium alloy, after the formation of a surface coating done.

Preferably is it in the inventive measuring device around a hand-held laser rangefinder.

The Inventive device is described below with reference to in the drawings schematically illustrated concrete embodiments purely by way of example described in more detail, where also on more Advantages of the invention is received. In detail show:

1 a hand-held laser range finder as an electro-optical measuring device;

2 an optical carrier body made of light metal according to the invention by means of thixomolding; and

3 a further embodiment of an optical carrier body according to the invention, which is installed in a non-illustrated housing of a hand-held electro-optical measuring device.

1 shows an electro-optical measuring device designed as a hand-held laser rangefinder 1 , This has a housing 5 and actuators 7 for switching the distance measuring device on or off as well as for starting or configuring a measuring process. In addition to the actuators 7 the meter has a display 6 for reproducing measurement results and device status information. Schematically and prinzi indicated implies the device has a transmission path 20 with a transmitter 21 for the emission of optical measuring beams 24 and an exit window 22 for the measuring beams 24 as well as a reception path 25 with a receiver 26 and a receiving optics 27 on.

The transmitter 21 , the exit window 22 , the recipient 26 and the receiving optics 27 are fastened inside the housing to an optical carrier body produced according to the invention by means of thixomolding. The optics carrier body lies in the housing so that the exit window 22 and the receiving optics 27 behind each opening of the housing 5 are arranged.

The optics carrier 10 has, in a manner to be described, a - for example cylindrically shaped - transmission channel between the transmitter and the exit window and a receiving channel between receiving optics and receiver, wherein in the receiving channel optionally a deflection means for deflecting the received beam may be arranged on the receiver. In addition, the optical carrier body is formed so that a part of the transmission beams as reference beams 29 be directed to the receiver before exiting the device.

The Measurement of distances is carried out according to the prior art Principles, such as B. the pulse transit time or phase comparison principle.

Of the Laser rangefinder can also further from the state of Technology known and customary components or functions exhibit.

2 shows a perspective view of an embodiment of an optical support body according to the invention as part of an electro-optical measuring device. According to the invention, the optical carrier body is produced in one piece from a magnesium alloy by means of thixomolding.

Of the Optics carrier has a number of shots for optical and / or electronic components of the measuring device on. So has the optics carrier on the rear facing Page a recording for an exit window and a Recording for a receiving optics, the reflected received measurement signal bundles on a receiver. The downward facing Side of the optics carrier is for receiving a printed circuit board, on which z. B. electronic components of an evaluation and the receiver are applied. Furthermore the optical carrier body has a tubular Transmitting channel and a tubular receiving channel, the the transmitting or receiving measuring beams relative to the housing interior of the meter. On or in the receiving channel can In this case, a deflecting means may be present which the received Beams to the receiver directs. In particular, that can Deflection means be designed as a filter, so that the optical measurement frequencies deflected, ambient and stray light but not in the direction of Receiver are redirected.

At the forward end of the transmission channel 23 is an attachment of a transmitter, the z. B. is designed as a laser diode on a small circuit board provided.

The broadcast channel 23 and the receiving channel 28 are in particular arranged side by side and parallel to each other, in which case the attachment of the transmitter is provided such that the transmission beam extends in the direction of the longitudinal axis of the transmission channel. The direction of the transmission beam defines the optical axis of the optical carrier body, which is usually adjusted so that it is aligned parallel to the longitudinal axis of the measuring device.

By the consistently bright and diffusely reflecting surface the thixomolding molded magnesium alloy improves and also simplifies diffuse reflections of the transmitted beams coupled to an inner wall of the transmission channel from the transmission path and as reference rays along a known path directly onto the Receiver to be steered. This allows the bright and not aging surface these diffuse reflections and thus this decoupling of the reference beam without further means, whereas in prior art devices in the usual special surface coatings be used with diffuse reflective properties or beam splitter. For example, the transmission channel for a decoupling, through which the diffused reflected rays from the transmission channel be extracted as reference beams on.

Favorable Way, the mentioned, at the optics carrier body to be attached components, such. B. the transmitter, a circuit board, the exit window and / or the receiving optics, already before one Assembly of the optics carrier body in the meter housing be attached to the optical carrier body. The inventive Formation of such an optical carrier body Thixomolding allows beyond that in detail, for example, pins or mounting ears for clipping form directly on the optical carrier body, so a simple, cost-effective and easy to install attachment said components on the optical carrier body and a simple installation of the optical carrier body can be made possible in the housing.

Due to the high stability, rigidity and Temperature resistance of the thixomolding optical carrier produced a high positional stability of the optical components is guaranteed to each other, while maintaining disadvantages in terms of manufacturing precision or weight compared to plastic-optical carriers.

Of the Optics carrier body according to the invention allows in an improved way the realization of a compact and lightweight, but still stable gauge, such as a hand-held electro-optical rangefinder, also with fluctuating temperatures, longtime use and even after a crash of the gauge on a hard Ground undamaged the optical components of the meter and stay fixed in their position.

3 shows a further embodiment of an inventive optical carrier body 10 already in an open case 5 a hand-held electro-optical measuring device is used. Other components of the meter, such as As batteries, display, input unit or evaluation, are not shown for ease of understanding and are known in the art.

The in 3 shown optics carrier body 10 In addition to the in 2 shown optical carrier body a recording 15 for a further module, for example for a digital camera, as well as a device for adjusting the optical axis of the optical carrier body relative to the housing of the measuring device in a vertical plane. The device for adjusting can in particular as a nose 13 for fixing a set screw 12 , being between nose 13 and housing 5 a preloaded spring 14 is, be trained. When installing the optics carrier body 10 in the case 5 can thus - by adjusting the set screw 12 - The optics carrier body 10 relative to the meter housing 5 slightly tilted so that the optical axis 11 parallel to the longitudinal axis of the meter housing 5 is easy and uncomplicated adjustable. Likewise, this also allows a later readjustment of the optical axis.

By the production of the optical carrier body 10 Thixomolding can easily break away from the set screw nose due to the stability and low porosity 13 at the optics carrier body 10 be prevented.

If the measuring instrument has an inclination sensor, this can additionally be used to adjust the optical axis 11 be used.

At the optics carrier body 10 is as a sender 21 already mounted a circuit board with a laser diode.

It It is understood that these figures shown only possible Represent exemplary embodiments schematically. The different Approaches can according to the invention with each other as well combined with devices of the prior art.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 19804050 A1 [0003, 0003]
• - DE 10157378 A1 [0004]
• - WO 2007/028667 [0005]

Claims (7)

Electro-optical measuring device ( 1 ), in particular hand-held and for non-contact distance measurement, with an optical transmission path ( 20 ), the at least one optical transmitter ( 21 ) for the emission of optical measuring beams ( 24 ), as well as with a reception path ( 25 ) with at least one receiving optics ( 27 ) for focusing reflected measuring beams in the direction of a receiver ( 26 ), and with a components of transmitting and receiving path receiving, in particular integrally formed optical carrier body ( 10 ), characterized in that the optical carrier body ( 10 ) consists of thixomolding shaped light metal. Electro-optical measuring device ( 1 ) according to claim 1, characterized in that the optical carrier body ( 10 ) consists of an aluminum or magnesium alloy. Electro-optical measuring device ( 1 ) according to one of the preceding claims, characterized in that the optical carrier body ( 10 ) for receiving the optical transmitter ( 21 ) and an exit window ( 22 ) and between the optical transmitter ( 21 ) and the exit window ( 22 ) a tubular transmission channel ( 23 ) with a reference beam opening for on an inner wall of the transmission channel ( 23 ) diffusely reflected measuring beams which are used as reference beams ( 29 ) to the recipient ( 26 ) are steered. Electro-optical measuring device ( 1 ) according to one of the preceding claims, characterized in that the optical carrier body ( 10 ) a recording ( 15 ) for another module, in particular for a digital camera. Electro-optical measuring device ( 1 ) according to one of the preceding claims, characterized in that the measuring device ( 1 ) has a tilt sensor. Electro-optical measuring device ( 1 ) according to one of the preceding claims, characterized in that the optical carrier body ( 10 ) so in a meter housing ( 5 ) is arranged such that an optical axis ( 11 ) of the optical carrier body ( 10 ) in at least one plane relative to the meter housing ( 5 ) is adjustable. Electro-optical measuring device ( 1 ) according to claim 6, characterized in that the optical carrier body ( 10 ) relative to the meter housing ( 5 ) is slightly tiltable about an axis, in particular wherein a tilted position of the optical carrier body ( 10 ) relative to the meter housing ( 5 ) by means of a set screw ( 12 ) is adjustable.