CN209894111U - Digital display electronic tape circuit with continuous coding mode - Google Patents

Abstract

The utility model relates to a digital display electronic tape circuit with a continuous coding mode, which comprises a code disc, a short circuit brush and an MCU; the coded disc is circular, and a first circular code channel, a second circular code channel and a third circular code channel are sequentially arranged on the surface of the coded disc from outside to inside; a plurality of first conductive copper foil blocks are printed on the first track at intervals, a plurality of second conductive copper foil blocks are printed on the second track at intervals, and conductive copper foils are printed on the third track integrally; the number of the first conductive copper foil blocks is equal to that of the second conductive copper foil blocks, and the first conductive copper foil blocks and the corresponding second conductive copper foil blocks are partially overlapped along the diameter direction of the code disc; the short circuit electric brush is in contact connection with the first track, the second track and the third track; the first code channel and the second code channel are electrically connected to the input end of the MCU, and the third code channel is grounded.

Description

Digital display electronic tape circuit with continuous coding mode

Technical Field

The utility model relates to a digital display electronic tape measure circuit, a digital display electronic tape measure circuit of continuous coding mode.

Background

The electronic tape measure can directly read the reading from the liquid crystal display screen, can realize the functions of switching display, data memory, Bluetooth transmission and the like of various units through internal software, and has the advantages which cannot be compared with the traditional mechanical tape measure. The scheme that the precision of the electronic measuring tape in the industry is higher at present usually adopts the same method as the disclosed double-sensor digital display measuring tape (patent application No. CN 03250083), a slideway with a unique angle and a discontinuous coding rule is adopted to equally divide the circumference, a circuit board is contacted with an electric brush, and when the measuring tape is pulled, the electric brush is driven to rotate to be contacted with the slideway to generate an angle code, and the angle code is used for calculating the length of an MCU (microprogrammed control Unit).

The electronic measuring tape on the market usually adopts 8 code tracks matched with an 8-pin electric brush or two 4-pin electric brushes to be used in parallel, the method is feasible, but the requirement on the precision degree of the manufacture of a circuit board and the electric brushes is very high, the thickness, the gap, the length and the bending angle of the electric brush pins can influence the measuring precision of the measuring tape, the pins and the pins must keep the consistency of the height, the higher the resolution ratio is, more slideways and more pins of electric brushes are needed, the consistency is more difficult to keep, the electric brushes can be directly scrapped if the electric brushes are carelessly protected to touch in the production process, and therefore the two four-pin electric brushes are actually used for reducing the production difficulty. The method needs to occupy more MCU ports, the size of the circuit board must be increased, otherwise, more code channels cannot be accommodated, and the brush contact short circuit code error is easily caused if the slide way is narrowed. In addition, 8 slideways are usually coded according to a certain rule by the circuit board code disc of the electronic tape measure and are evenly divided into 256 angles to be distributed to 8 IO ports of the MCU to realize the identification of 0-255, the codes of fixed angles are unique and disordered and are not continuously increased or decreased, the MCU needs to establish disordered numbers into an array, the disordered numbers are converted into a continuously increased or decreased array to be calculated by a mode of looking up the table and returning array bit numbers, a large amount of time is undoubtedly consumed, if the tape measure MCU is pulled quickly, the response is not timely caused, the counting is missed, and the clock frequency of the MCU is increased, so that the MCU consumes more power.

SUMMERY OF THE UTILITY MODEL

In order to solve the problem that exists among the above-mentioned prior art, the utility model provides a digital display electronic tape circuit of continuous coding mode can carry out continuous coding, adopts the pulse to add up the count, compares with the coding mode that converts again with only coding value in every position in the common circumference on the market, has reduced the production degree of difficulty and technology widely.

The technical scheme of the utility model as follows:

a digital display electronic tape circuit adopting a continuous coding mode comprises a code wheel, a short-circuit electric brush and an MCU; the coded disc is circular, and a first circular code channel, a second circular code channel and a third circular code channel are sequentially arranged on the surface of the coded disc from outside to inside; a plurality of first conductive copper foil blocks are printed on the first track at intervals, a plurality of second conductive copper foil blocks are printed on the second track at intervals, and conductive copper foils are printed on the third track integrally; the number of the first conductive copper foil blocks is equal to that of the second conductive copper foil blocks, and the first conductive copper foil blocks and the corresponding second conductive copper foil blocks are partially overlapped along the diameter direction of the code disc; the short circuit electric brush is in contact connection with the first track, the second track and the third track; the first code channel and the second code channel are electrically connected to the input end of the MCU, and the third code channel is grounded.

Furthermore, a circular fourth code channel is arranged on the inner side of the third code channel, and a plurality of third conductive copper foil blocks are arranged on the fourth code channel at intervals; the short circuit electric brush is also in contact connection with the fourth track; the fourth code channel is electrically connected to the input end of the MCU; the distance between every two adjacent third conductive copper foil blocks is the same, and the distance between every two adjacent third conductive copper foil blocks is larger than the width of each third conductive copper foil block.

Furthermore, the distance between two adjacent first conductive copper foil blocks is the same, and the distance between two adjacent first conductive copper foil blocks is equal to the width of the first conductive copper foil blocks; the distance between two adjacent second conductive copper foil blocks is the same, and the distance between two adjacent second conductive copper foil blocks is equal to the width of the second conductive copper foil blocks.

The utility model discloses following beneficial effect has:

1. the utility model discloses a set up the electrically conductive copper foil piece that the dislocation overlaps in first sign indicating number way and second sign indicating number way, realize can carrying out the continuous coding, adopt the pulse to add up the count, all compare with the coding mode that converts again with only coding value in every position in a common circumference on the market, only need just can realize the resolution ratio that 8 sign indicating numbers way products could reach on the market with 3 sign indicating numbers ways, reduced the production degree of difficulty and technology widely.

2. The utility model discloses a set up the fourth sign indicating number, differentiate whether the short circuit brush is rotatory, automatic start opens the liquid crystal display function when can realizing the tape measure pulling, closes the liquid crystal and saves the consumption when stopping the pulling, need not special switch key.

Drawings

Fig. 1 is a schematic connection diagram of the present invention;

FIG. 2 is a schematic diagram of a printed circuit board of a code disc of an embodiment of the present invention;

fig. 3 is a schematic connection diagram of the present invention.

The reference numbers in the figures denote:

1. code disc; 11. a first code channel; 111. a first conductive copper foil block; 12. a second code channel; 121. a second conductive copper foil block; 13. a third code channel; 14. a fourth code channel; 141. a third conductive copper foil block; 2. a short circuit brush; 3. and (6) an MCU.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

Referring to fig. 1 and 3, a digital display electronic tape circuit with a continuous coding mode comprises a code disc 1, a short circuit brush 2 and an MCU 3; the coded disc 1 is circular, and a first code channel 11, a second code channel 12 and a third code channel 13 which are circular in shape are sequentially arranged on the surface of the coded disc from outside to inside; a plurality of first conductive copper foil blocks 111 are printed on the first track 11 at intervals, a plurality of second conductive copper foil blocks 112 are printed on the second track 12 at intervals, and a conductive copper foil is printed on the third track 13 integrally; the number of the first conductive copper foil blocks 111 is equal to that of the second conductive copper foil blocks 112, and the first conductive copper foil blocks 111 and the corresponding second conductive copper foil blocks 112 are in one-to-one correspondence, and are partially overlapped along the diameter direction of the code wheel 1 (see a DD' line in FIG. 2); the short circuit electric brush 2 is in contact connection with the first track 11, the second track 12 and the third track 13; the first code channel 11 and the second code channel 12 are electrically connected to the input end of the MCU3, that is, the first code channel 11 and the second code channel 12 are electrically connected to two I/O ports of the MCU3, respectively, and the third code channel 13 is grounded.

Further, a circular fourth code channel 14 is further arranged on the inner side of the third code channel 13, and a plurality of third conductive copper foil blocks 141 are arranged on the fourth code channel 14 at intervals; the short-circuit brush 2 is also connected with a contact; the fourth code channel 14 is electrically connected to the input end of the MCU3, that is, the fourth code channel 14 is connected to an I/O port of the MCU3 (another I/O port other than the two I/O ports); the distance between the two third conductive copper foil blocks 141 is the same, and the distance between the two third conductive copper foil blocks 141 is greater than the width of the third conductive copper foil blocks 141.

Further, the distance between the two first conductive copper foil blocks 111 is the same, and the distance between the two first conductive copper foil blocks 111 is equal to the width of the first conductive copper foil blocks 111; the distance between the two second conductive copper foil blocks 112 is the same, and the distance between the two second conductive copper foil blocks 112 is equal to the width of the second conductive copper foil blocks 112.

The utility model discloses a work flow as follows:

in the present embodiment, as shown in fig. 2, the first track 11 and the second track 12 are divided into 128 small blocks with equal black and white intervals, the black part represents the conductive copper foil block which can be conductive, and the white part is not conductive. The first code channel 11, the second code channel 12 and the fourth code channel 14 are respectively connected to three I/O ports of the MCU3, the third code channel 3 is grounded, in this embodiment, three I/O ports of the MCU3 are respectively provided with a pull-up resistor, and when the short-circuit brush 2 slides to an I/O port corresponding to the conductive copper foil, the short-circuit brush will receive a low level to ground, otherwise, the short-circuit brush is a high level. When the short-circuit brush 2 rotates clockwise, which is equivalent to that the short-circuit brush 2 moves rightwards in fig. 3, the I/O ports connected with the first track 11 and the second track 12 circularly receive the changing state of 11-10-00-01 … … 11-10-00-01, whereas when the short-circuit brush 2 rotates anticlockwise, the I/O ports connected with the first track 11 and the second track 12 receive the changing state of 01-00-10-11 … … 01-00-10-11 opposite to that when the short-circuit brush 2 rotates clockwise, the changing level of the next advance or retreat at each state point is unique, the MCU3 identifies whether the short-circuit brush 2 rotates clockwise or anticlockwise, namely, determines whether the tape measure is pulling out or retracting, and can realize continuous direct counting by adding or subtracting the length variable, the counting is converted without coding and table look-up, the resolution of one circle is 256, 256 counts can be realized, the tape can identify the resolution less than 1mm, the efficiency of the MCU3 is greatly improved, and the counting is not easy to miss when the tape is pulled at high speed. Compared with the common encoding mode that every position in a circle is converted by a unique encoding value, the resolution ratio which can be achieved by 8 code channel products on the market can be realized by only using 3 code channels, and the production difficulty and the process are greatly reduced. If the code wheel is divided into more cells, higher resolution can be achieved, but the slide way and the electric brush are not required to be added.

In order to save power consumption, the MCU3 goes to sleep immediately when the tape measure is not pulled, since the I/O ports connected to the first track 11 and the second track 12 are both provided with pull-up resistors, there may be a situation where two I/O ports are simultaneously in contact with a low level, which may consume power of two I/O ports, in order to achieve optimal power consumption, the present embodiment adds the fourth track 14, sets the I/O ports connected to the first track 11 and the second track 12 to be at a low level in the output direction during sleep, sets only the I/O port connected to the fourth track 14 as a pull-up input, and immediately wakes up the MCU3 to perform a counting operation when the I/O port connected to the fourth track 14 detects a level change, only one I/O port may be grounded, which reduces power consumption by half. The method can realize the function of automatically starting up and starting up the liquid crystal display screen when the tape is pulled, and can save power consumption by closing the liquid crystal screen when the tape is not pulled, and a special startup key is not needed.

The above only is the embodiment of the present invention, not limiting the patent scope of the present invention, all the equivalent structures or equivalent processes that are used in the specification and the attached drawings or directly or indirectly applied to other related technical fields are included in the patent protection scope of the present invention.

Claims (3)

1. A digital display electronic tape circuit with a continuous coding mode is characterized in that: the device comprises a code disc (1), a short circuit electric brush (2) and an MCU (3); the coded disc (1) is circular, and a first circular code channel (11), a second circular code channel (12) and a third circular code channel (13) are sequentially arranged on the surface of the coded disc from outside to inside; a plurality of first conductive copper foil blocks (111) are printed on the first code channel (11) at intervals, a plurality of second conductive copper foil blocks (112) are printed on the second code channel (12) at intervals, and conductive copper foils are printed on the third code channel (13) integrally; the number of the first conductive copper foil blocks (111) is equal to that of the second conductive copper foil blocks (112), and the first conductive copper foil blocks (111) and the corresponding second conductive copper foil blocks (112) are partially overlapped along the diameter direction of the code disc (1); the short circuit electric brush (2) is in contact connection with the first track (11), the second track (12) and the third track (13); the first code channel (11) and the second code channel (12) are electrically connected to the input end of the MCU (3), and the third code channel (13) is grounded.

2. The digital display electronic tape measure circuit adopting the continuous coding mode as claimed in claim 1, wherein: the inner side of the third code channel (13) is also provided with a circular fourth code channel (14), a plurality of third conductive copper foil blocks (141) are arranged on the fourth code channel (14) at intervals, and the fourth code channel (14) is electrically connected to the input end of the MCU (3); the short circuit electric brush (2) is also in contact connection with the fourth track (14); the distance between two adjacent third conductive copper foil blocks (141) is the same, and the distance between two adjacent third conductive copper foil blocks (141) is larger than the width of the third conductive copper foil blocks (141).

3. The digital display electronic tape measure circuit adopting the continuous coding mode as claimed in claim 1, wherein: the distance between two adjacent first conductive copper foil blocks (111) is the same, and the distance between two adjacent first conductive copper foil blocks (111) is equal to the width of the first conductive copper foil blocks (111); the distance between two adjacent second conductive copper foil blocks (112) is the same, and the distance between two adjacent second conductive copper foil blocks (112) is equal to the width of the second conductive copper foil blocks (112).

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