back-of-hand scanner

Abstract

A back-of-hand scanner (1) with an optical reading device (26) for reading a barcode on an object in a reading direction (7) in front of the back-of-hand scanner (1) and a trigger (27) which has an optical distance sensor (33) and triggers the reading device (26) when the distance sensor (33) detects a distance of the back-of-hand scanner (1) to the object below a limit distance, characterized in that the trigger (27) has an inertial sensor which includes acceleration and rotation rate sensors and detects translation in three independent spatial directions and rotation about the spatial directions and triggers the reading device (26) only when the inertial sensor detects a linear movement of the back-of-hand scanner (1) in the reading direction (7), wherein the trigger (27) blocks the triggering of the reading device (26) when the inertial sensor detects a rotation of the back-of-hand scanner (1).

Description

[0001] The invention relates to a back-of-the-hand scanner with an optical reading device for reading a barcode on an object in a reading direction in front of the back-of-the-hand scanner and a trigger which has an optical distance sensor and triggers the reading device when the distance sensor detects a distance of the back-of-the-hand scanner to the object below a limit distance.

[0002] A back-of-hand scanner of the aforementioned type is known from the applicant's portfolio under the product name "Voxter Scan Elite": The trigger of the known back-of-hand scanner has an optical button. The known back-of-hand scanner is connected via Bluetooth in a picking system to a portable control unit, which gives an operator voice instructions via a headset to pick items from a warehouse as specified in a pick list.

[0003] False triggers of the reading device due to accidental proximity to floors, walls or shelf elements increase energy consumption and reduce the operating time of the familiar back-of-the-hand scanner.

[0004] US 5,534,684 A and US 2014 / 0062673 A1 propose triggering a portable barcode scanner based on a distance measurement. US 2010 / 0274524 A1 proposes triggering when the device is at rest.

[0005] In the background of the invention, US 2016 / 0132707 A1 discloses a scanner attached to an operator's head. US 2015 / 0015502 A1 proposes a fitness tracker with an inertial sensor to detect the movements of a person wearing the device and with a reading device for reading a barcode on a packaged food product.

[0006] In the further background of the invention, US 2017 / 0262678 A1 discloses a back-of-the-hand scanner to be worn on a finger, the reading device of which is triggered by pressing a button. Task

[0007] The invention is based on the objective of avoiding false triggering of the reading device. Solution

[0008] Based on the known back-of-hand scanner, the invention proposes that the trigger has an inertial sensor comprising acceleration and rotation rate sensors, which detects translation in three independent spatial directions and rotation about the spatial directions, and triggers the reading device only when the inertial sensor detects a linear movement of the back-of-hand scanner other than in the reading direction, wherein the trigger blocks the triggering of the reading device when the inertial sensor detects a rotation of the back-of-hand scanner.

[0009] An inertial sensor (also: inertial measurement unit, IMU) is a combination of accelerometers and gyroscopes that together are able to detect motion components in several of the six kinematic degrees of freedom: translation in three independent, usually mutually perpendicular spatial directions (forward or backward, sideways and up or down) and rotation about these directions (roll, pitch and yaw).

[0010] The reading device of the back-of-hand scanner according to the invention is only triggered if the hand points in a constant direction towards a point in space for an individually adjustable period of time and is either not moved at all or only moved forward in this direction – towards the point. Such a movement pattern is interpreted as "aiming" at the point. False triggers caused by accidentally passing laterally by an object located within the limit distance are thus reliably avoided. Minor translational movements below an individually adjustable threshold are not recognized as movement.

[0011] When aimed at a point in space, the back-of-the-hand scanner does not perform any rotational movement. Minor rotational movements below a user-defined threshold are not detected as movement.

[0012] Preferably, in a back-of-hand scanner according to the invention, the inertial sensor is an integrated component. Integrated IMUs allow for a small size of the back-of-hand scanner and are available on the market in various designs at a low cost.

[0013] Preferably, in a back-of-the-hand scanner according to the invention, the distance sensor comprises an infrared diode and an infrared photodiode. A signal emitted by the infrared diode in the reading direction is reflected by an object located in that direction, and the reflected signal is detected by the infrared photodiode. The distance sensor calculates the distance to the object from the luminous intensity of the reflected signal. Infrared distance measurement is known from the prior art for back-of-the-hand scanners and avoids both the risk of eye damage and measurement errors caused by light reflections. Alternatively or additionally, the distance sensor can, for example, include a radar measuring unit that measures the distance to the targeted point using radio waves. Alternatively or additionally, the distance sensor can also include a laser emitting visible light, which simultaneously visibly marks the targeted point during the measurement process.

[0014] Preferably, a back-of-hand scanner according to the invention has a holding element for attaching it to the back of an operator's hand. Such a holding element can, for example, be a clamp encircling the back of the hand, a strap, or an elastic band. Alternatively, a back-of-hand scanner according to the invention can be integrated into a glove.

[0015] Preferably, a back-of-hand scanner according to the invention comprises a wireless communication module. Such a back-of-hand scanner does not require cables for transmitting data, for example, to and / or from a control unit. In particular, such a communication module can establish a near-field connection, for example, according to the Bluetooth standard, or a network connection (WLAN).

[0016] Preferably, a back-of-the-hand scanner according to the invention has a removable energy storage device. Such a back-of-the-hand scanner can be used with another (already charged) energy storage device while one energy storage device is being charged.

[0017] Preferably, a back-of-the-hand scanner according to the invention has a dustproof and splashproof housing. Such a back-of-the-hand scanner is also suitable for use in humid environments and / or under strong temperature fluctuations.

[0018] Preferably, a back-of-the-hand scanner according to the invention is connected to a control unit of a picking system that provides a pick list of items to be retrieved from a warehouse. The picking system according to the invention also features the aforementioned advantages of the back-of-the-hand scanner according to the invention.

[0019] Preferably, such a picking system according to the invention comprises a headset connected to the control unit, wherein the control unit gives an operator acoustic instructions via the headset to pick up an item from the pick list. Such a picking system according to the invention enables the picking list to be processed solely on the basis of acoustic instructions. Example of implementation

[0020] The invention is explained below using an exemplary embodiment. Figures show... Fig. 1a / b two views of a back-of-the-hand scanner according to the invention, Fig. 2a-d four detailed views of the back-of-the-hand scanner according to the invention and Fig. 3a / b two further detailed views of the back-of-the-hand scanner according to the invention.

[0021] The one in the Fig. 1a and Fig. The approximately cuboid-shaped back-of-hand scanner 1 shown in Figure 1b comprises a scanner module 2 and a battery module 3 and is mounted on a mounting plate 4. In the assembled state, the scanner module 2 and the battery module 3 are dustproof and splashproof.

[0022] The scanner module 2 comprises a housing 5 and a cover 6 that closes the housing 5. On a front face 8, the housing 5 of the scanner module 2 has two adjacent openings 9 in a reading direction 7, which are closed with discs 10 transparent to infrared radiation. Below these openings 9, the housing 5 of the scanner module 2 has another opening 11, which is closed with a disc 12 transparent to visible light. On a side wall opposite the cover 6, the housing 5 of the scanner module 2 has a push button 14 for activating and deactivating the back-of-hand scanner 1.

[0023] Fig. Figure 2a shows the back-of-hand scanner 1 removed from the mounting plate 4: The back-of-hand scanner 1 has on one underside 15 two pairs of bar blocks 16 arranged one behind the other in the reading direction 7, each facing outwards.

[0024] Fig. Figure 2b shows the scanner module 2 after removal of the battery module 3: The cover 6 of the scanner module 2 has a circumferential rim 17 and an opening 18 for a contact element 19 with four plug contacts 20 and is connected to the housing 5 of the scanner module 2 with two screws.

[0025] The Fig. 2c and Fig. Figure 2d shows the housing 5 of the scanner module 2 and the scan unit 22, which is inserted into this housing 5 in its assembled state. The scan unit 22 is based on a rigid-flexible circuit board 23 with a central mainboard 24, to which, among other things, the contact element 19 and a communication module 25 (not shown in detail) with an NXP PN7150 NFC IC and an NFC antenna are flexibly attached. The scan unit 22 includes, in particular, an optical reader 26 and a trigger 27. For signaling operating states, the scan unit 22 has a light-emitting diode 28, the optical signal of which is guided via a light guide 29 to a top surface 30 of the back-of-hand scanner 1, and a vibration element 31 for haptic feedback.

[0026] The reading device 26, which is not shown in detail, consists of a Zebra SE4750 imager and a PL3307-C decoder board from the same manufacturer and, with a current consumption of 500 mA, is the largest energy consumer in the back-of-hand scanner 1. A camera eye 32 of the imager is arranged behind the visible light-transmitting disc 12 on the front 8 of the scanner module 2.

[0027] The trigger 27 includes an optical distance sensor 33 with a Vishay VSLB3940 infrared diode 34 and a TSSP58P38 infrared photodiode 35 from the same manufacturer. The infrared diode 34 and the infrared photodiode 35 are mounted separately behind the infrared-transmitting disks 10 on the front 8 of the scanner module 2. The trigger 27 also includes an inertial sensor (not shown) consisting essentially of an NXP FXOS8700CQ accelerometer and an FXAS21002C gyroscope from the same manufacturer.

[0028] As in Fig. As shown in Figure 3a, the battery module 3 also has a housing 36 and a cover 36 that closes the housing 36, which in the assembled state of the Fig. 1a / b is located in the circumferential rim 17 of the cover 6 of the scanner module 2. The cover 36 of the battery module 3 has four sockets 38 for receiving the plug contacts 20 of the scanner module 2. To charge the battery module 3, it is placed on a charger whose plug contacts also engage in the sockets 38. Inside the housing 36, the battery module 3 has an energy storage device for electrical energy. The charger with the charging electronics and the energy storage device are not shown.

[0029] Fig.Figure 3b shows the mounting plate 4 for the back-of-hand scanner 1 in detail: The mounting plate 4 has a slightly curved underside 39 transverse to the reading direction 7, and on the upper side 30, four recesses 40 and a latch 41 that can be moved transversely to the reading direction 7. Openings 42 are arranged on the underside 39 through which the mounting plate 4 can be sewn onto a glove (not shown). The back-of-hand scanner 1 is placed onto the mounting plate 4 such that the latch blocks 16 are inserted into the recesses 40 and locked by means of lugs 43 arranged on the mounting plate 4 and on the latch 41. To release the lock, the latch 41 is moved transversely to the reading direction 7 via an end 44 projecting from the mounting plate 4 against a spring element (not shown).

[0030] The back-of-hand scanner 1 is used in a picking system (not shown) together with a control unit and a headset: An operator wears the control unit on their belt, a glove with the back-of-hand scanner 1 on one hand, and the headset on their head. The headset is connected to the control unit via a cable.

[0031] After the scanner module 2 is connected to a charged battery module 3, the LED 28 flashes green to indicate operational readiness. After pressing button 14, the flashing signal changes to red-green, and the back-of-hand scanner 1 establishes a connection to the control unit via the communication module 25. Once the connection is established, the vibration element 31 vibrates briefly, the LED 28 glows steadily green, and the control unit reports "Scanner ready" via the headset. The reading device 26 is initially in energy-saving mode. During the subsequent picking process, the operator hears the picking instructions and confirms each one by voice input via the headset.

[0032] As soon as a picking instruction is issued, the trigger 27 queries the distance sensor 33 every millisecond. Only when the distance measured by the distance sensor 33 falls below a limit value individually set for the operator in the control unit – a typical starting value for training is 15 cm – is the inertial sensor evaluated. Only if the inertial sensor then detects no movement of the back-of-hand scanner 1 (exceeding limits also individually set for the operator), except in the reading direction 7, is the reading device 26 activated for an individually set period – for example, 5 seconds by default. If a barcode is detected, it is transmitted to the control unit via the communication module 25, and the reading device 26 is returned to energy-saving mode.

[0033] Compared to the state of the art, the back-of-the-hand scanner 1 has an energy consumption that is approximately 20% lower.

[0034] The characters are 1 back-of-hand scanner 2 Scanner module 3 battery modules 4 Mounting plate 5 Housing (Scanner module) 6 lids (scanner module) 7 Reading direction 8 Front 9 Opening (distance meter) 10 discs (distance measuring devices) 11 Opening (reading device) 12 discs (reading device) 13 Side wall 14 buttons 15 Underside 16 bar block 17 Rand 18 Breakthrough 19 Contact element 20 plug contacts 21 screw 22 Scan unit 23 Circuit board 24 Mainboard 25 Communication module 26 Reading device 27 triggers 28 light-emitting diodes 29 optical fibers 30 Top 31 Vibration element 32 camera eye 33 distance meters 34 Infrared diode 35 Infrared photodiode 36 Housing (battery module) 37 Cover (battery module) 38 socket 39 Underside 40 trough 41 bars 42 Opening 43 Nose 44 End

Claims

[1] Back-of-hand scanner (1) with an optical reading device (26) for reading a barcode on an object in a reading direction (7) in front of the back-of-hand scanner (1) and a trigger (27) which has an optical distance sensor (33) and triggers the reading device (26) when the distance sensor (33) detects a distance of the back-of-hand scanner (1) to the object below a limit distance, characterized by , that the trigger (27) has an inertial sensor comprising acceleration and rotation rate sensors and detects translation in three independent spatial directions and rotation about the spatial directions and only triggers the reading device (26) when the inertial sensor detects a linear movement of the back-of-hand scanner (1) in the reading direction (7), wherein the trigger (27) blocks the triggering of the reading device (26) when the inertial sensor detects a rotation of the back-of-hand scanner (1). [2] Back-of-hand scanner (1) according to the aforementioned claim, characterized bythat the inertial sensor is an integrated component. [3] Back-of-hand scanner (1) according to any of the preceding claims, characterized by , that the distance meter (33) has an infrared diode (34) and an infrared photodiode (35). [4] Back-of-hand scanner (1) according to any of the preceding claims, characterized by a holding element for attaching to the back of an operator's hand. [5] Back-of-hand scanner (1) according to any of the preceding claims, characterized by a wireless communication module (25). [6] Back-of-hand scanner (1) according to any of the preceding claims, characterized by a removable energy storage device. [7] Back-of-hand scanner (1) according to any of the preceding claims, characterized by a dustproof and splashproof housing (5, 36). [8] Picking system comprising a control unit which provides a pick list of items to be picked from a warehouse and a back-of-hand scanner (1) connected to the control unit according to one of the preceding claims. [9] Order picking system according to the aforementioned claim, characterized by a headset connected to the control unit, wherein the control unit gives an operator acoustic instructions via the headset to pick up an item from the pick list.

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