Optical encoding device. RU patent 2507559.

FIELD: physics.

SUBSTANCE: device has two elements that are movable relative each other, the first element (10) having at least one mark (16), and the second element (11) is fitted with a pair of photocells (17, 18) for detecting the mark (16), wherein the dimensions of the mark (16) are such that it cannot be detected by any of the two photocells (17, 18) or it can be detected by only one photocell (17, 18) or by both photocells (17, 18). The length of the zone of the second element (11), having a pair of detection photocells (17, 18), is shorter than the length of the mark (16). The lengths are measured in the direction of relative displacement of the two elements (10, 11), and the tolerance of the length of the mark is in the range from the minimum length, equal to the length of the zone, to the maximum length of the mark, which does not depend on the length of the zone and depends on the number of increments of the encoding device.

EFFECT: easy manufacture of the device owing to a larger tolerance of making marks and the tolerance of positioning the photocells.

16 cl, 7 dwg

The technical field

The present invention relates to optical encoding devices issuing logical binary signals, characterizing increment relative position of the two elements of the encoder, both are movable relative to each other. These optical encoding device, such as a corner coding devices, use like potentiometers, for example, for manual control electronic devices are sensitive to the input parameter, which can continuously or almost continuously change, but they are much more reliable than potentiometers. Usually applied to aircraft equipment you can use the optical encoder for the introduction of a computing device autopilot setpoint flight altitude or speed that the pilot selects with the control button, which brings into action encoder. Reliability of the encoder and the data it transmits, are the main element of the encoder.

Prior art

Usually optical encoder contains the disk which uniformly implemented labels, this CD to give effect to the rotation with the control button (for example, manual). Photocell, mounted in front of the disk, detects the steady flow of the marks when the control button activates the disk. Usually the marks are in the form of holes in opaque disk, the disk is installed, the led, and on the other side of the drive is installed photocell.

Each passage marks correspond to increase per unit in the reference system of rotation. The angular resolution of the defined angular step marks, evenly distributed on the turnover of the disk. To detect how the increments and decrements the angle of rotation, when changing the direction of rotation, there are two solar cell, physically offset by an odd number of quarters step between them. Thus, the logical state of «lit/is not lit» two photocells encode two bits, which give the following four successive values: 00, 01, 11, 10, when the disc rotates in one direction, and the following four successive values of 00, 10, 11, 01, when the disk is rotating in the other direction, so it is easy to determine not only the appearance of rotation increment (change in the state of bits), but also the direction of rotation (by comparison between one state of elements and its preceding state.

These encoding devices requiring high accuracy of manufacturing. In particular, the relative position of photocells, depend on the increment. The same applies to the disk, whose dimensions and position of each hole where must conform to the dimensions and position of photocells.

A brief description of the nature of the invention

The present invention is designed to simplify the execution of optical encoder due to expansion of the manufacturing tolerances of some elements of the encoder in particular tolerances positioning the solar cells, as well as the size tolerances and the provisions of the holes of the disk.

In this regard, the object of the present invention is incremental optical encoder, containing two elements, moving relative to each other, while the first element contains at least one tag and the second element is installed pair of photocells detection labels, characterized in that the size of the marks specified in such a way that they either could not detect any of the cell, or you can detect only one cell, or both solar cells, and the length of the second element that contains a couple of detection photocells, less label length, the length measured in the direction of the relative movement of two elements.

The length of the zone and labels can be distance, if the relative motion of the two elements is linear. Length can be angled relative movement is revolving.

Due to this increase tolerance for manufacturing labels. Indeed, the minimum length of the label is the length of the zone. On the other hand, the maximum length of a label is not associated with the length of the zones and depends only on the number of increments of the encoder.

Successive increments of the encoder are determined, for example, the detection of tags:

- none of the cells,

- then the first of photocells

- then both photocells at the same time.

The increment of the following increments defined by detecting labels simultaneously by two photocells, determined, for example, the detection of tags:

- the second of photocells

- then none of photocells.

Brief description of drawings

The invention is further explained in the description of the preferred way to implement them, with reference to the accompanying drawings, in which:

Fig. 1A-1d depict different relative positions of two elements, moving relative to each other, the angular encoder in accordance with the present invention;

Fig. 1E specifies the relative length of the mark for the first element relative to the zone containing the detection photocells of the label;

Fig. 2 depicts encoding captured with the help of two photocells detection of coding devices;

Fig. 3 shows the General view of the examples of the implementation of the angular encoder.

Description of preferred options for carrying out the invention

Description is presented for the angular encoder. Of course, the invention can also be used in a linear device.

In Fig. 1A-1d shows the four provisions of the angular encoder contains two moving relative to each other item 10 and 11. The first item is a CD 10, rotating around the axis of 12. The second element of 11 forms the body of the encoder. Axis 12 is turning the button that the user can trigger to enter binary data by using the encoder. Encoder allows you to determine the angular position of the disc 10 relative to the housing 11 when the disc is spinning around 10 12 axis depending on the increment.

Preferably encoder contains products for mechanical detect stable provisions of the two items 10 and 11 for each other. In the case of angular encoder these tools contain, for example, internal gear 13, permanently connected to the body of 11, and 14 ball, associated with the disc 10. Ball 14 may freely move forward movement on the disk 10 in the radial direction 15 disk. Ball 14 may move from one tooth of wheels 13 to another. The ball 14 may act pushing force not shown spring to hold it in the recess of each tooth. Stable position of the disc 10 relative to the housing 11 are defined by provisions ball 14 in the recess of each tooth of wheels 13.

Disc 10 contains consistently made holes 16, between which the disc 10 is continuous. Each hole 16 forms a label on the disk, and continuous space separating each hole, characterizes the lack of label. In other words, disk contains 10 alternation marks 16 and the absence of marks. Labels are located radially around the axis of 12. Disc 10 you can also perform a solid material without holes, alternating in the radial direction transparent zone, forming the mark and opaque area. In the future, transparent areas will be equal to the holes 16. Of course, the invention can be used when only one label on disk 10.

Building 11 contains a couple of photocells 17 and 18 detection label 16. In this example, the encoder also contains optical emitter, made with the possibility of detecting two photocells 17 or 18 detection. In the version of the encoder can contain two optical emitter, each of which can be detected by one of the photocells 17 or 18 detection. The disk can be moved between the emitter or radiators, on the one hand, and photocells 17 or 18, on the other hand. Emitter or radiators are made, for example, in the form of electroluminescent diodes, solar cells 17 and 18 are photodiodes, sensitive to the radiation of a diode or diodes. In the variant when the encoder contains two electroluminescent diodes, it is important that each photocell 17 or 18 was sensitive only to a single diode.

The necessity of detecting separately each of photocells 17 and 18 determines the minimum distance separating solar cells 17 and 18, on the one hand, and, if necessary, diodes, on the other hand. This distance should ensure that the label or not was detected by any of the cell, or was detected in one of the cell, or both solar cells, 17 and 18. In other words, you want the edge of the same label 16 couldn't stop between the two photocells 17 and 18 at the time of rotation of the disc 10. In the presence of an alternating sequence of labels 16 and lack of label 16 pair of photocells 17 and 18 can detect each mark 16 regardless of the next. Detection label 16 happens on its edge. Thus, the length of the label 16 does not affect the detection label 16. Therefore, you can extend the manufacturing tolerances label 16. Maximum label length 16 depends only on the number of increments of the encoder. In Fig. 1E shows a magnified view of the Fig. 1C shows the angular length α label 16, which should be more angular length β zone 19, contains a couple of photocells 17 and 18 detection. In other words, zone 19 is a minimum area of land occupied by both solar cells, 17 and 18, including the area between the solar cells, 17 and 18.

On the other hand, the invention is not imposes no maximum limit for the distance that separates solar cells 17 and 18. There is only a maximum limit for the location of a sufficient number of increments on the disk 10.

In addition, the relative position of the two photocells 17 and 18 does not depend on the number of increments. Therefore, you can standardize bracket photocells 17 and 18 for different coding devices with different step increments.

During the movement of the disc 10 around its axis every 12 photocell 17 and 18 catches or unable to detect radiation from the corresponding diode depending on the presence or absence of openings between 16 photocell 17 or 18 and its corresponding diode.

In Fig. 1A both photocell 17 and 18 are closed CD 10. In Fig. 1b photocell 17 lit, and photocell 18 closed. On fig.1 both photocell 17 and 18, lit. In Fig. 1d photocell 17 closed and photocell 18 lit.

The four Fig. 1A-1d shown on the order of four consecutive stable position when the disc is spinning around 10 axis 12 clockwise. In the position following the situation shown in Fig. 1d, the disc closes both photocell 17 and 18. This provision corresponds to the situation shown in Fig. 1A. Of course, the disc can be rotated in direction. In this case, get a reverse the order of the lighting and closing photocells 17 and 18.

In Fig. 2 shows the encoding captured with the help of two photocells 17 and 18 detection depending on stable positions on 10 relative to the housing 11. In the upper part of figure 2 shows eight of stable conditions, as the numbers from 1 to 8. Broken sawtooth line 20 shows the teeth of the wheels 13. Curve 27 characterizes encoding obtained with a photocell 17, but the curve 28 shows the encoding obtained with a photocell 18. Coding captured with the help of solar cells 17 and 18 is the binary and can take the values denoted by 0 and 1. Coding obtained with a photocell 17, takes on the value 0 to the provisions of 1, 2, 5 and 6 and a value of 1 to the provisions of 3, 4, 7 and 8. Coding obtained with a photocell 18, takes on the value 0 to the provisions of 1, 4, 5 and 8 and a value of 1 to the provisions of 2, 3, 6 and 7.

The provisions of 1 and 5 are consistent with the provisions shown on the fig.1. The provisions of 2 and 6 correspond to the provisions shown in Fig. 1d. The provisions of 3 and 7 correspond to the provisions shown in Fig. 1C. Principles 4 and 8 are consistent with the provisions shown in Fig. 1d. The order of the provisions from 1 to 8 corresponds to the rotation of the disc 10 in direction, as determined with the help of Fig. 1A-1d.

In Fig. 3 in term illustrates an example of the angular encoder contains two emitter and two solar cell on 17 and 18, permanently United with bracket 30 U-shaped. Bracket 30 contains two located against each other branches 31 and 32. Radiators are on one of the branches of 31 U, and solar cells 17 and 18 are installed on another branch 32 U. Disk 10 moves between the branches of U. When a disk 32 rotates around its axis 12, opening 16 pass between the branches of the bracket 30 so that they could detect solar cells 17 and 18. With the disc 10 motionless connected shaft 33, passing along the axis of 12. Val 33 related to the corps 11 support bearing, leaving a degree of freedom of rotation around the axis 12. Val 33 allows the operator to rotate the disc 10.

Preferably bracket 30 motionless is connected to a Board 34 printed circuit, which allows the connections required for operation of emitters and photocells 17 and 18. On Board 34 you can also position the electronic components associated with the processing of data encoded using solar cells 17 and 18. Fee 34 is, for example, in a plane parallel to the axis of 12.

Preferably for redundancy coding can be duplicated bracket 30. On the second bracket 30 also establish two emitter and two solar cell on 17 and 18. The second bracket 30 can also be arranged on Board 34 printed circuit. To improve the compactness of the encoder both cards 34 can be put in parallel. More generally, encoder contains two second element, moving relative to only the first element that contains at least two labels, with each of the two main elements of paired detection photocells one of the two marks, that provides redundancy detection marks. Indeed, Board 34 have a level of reliability is lower than the level of reliability of disk 10. To improve the reliability of the encoder enough duplicate card 34 around one disc 10. This duplication can also be used for detection of malfunctions of the charge components 34 when the encoding is issued to each of the pairs of photocells 17 and 18, is different.

2. Encoder device according to claim 1, characterized in that the successive increments of encoder defined, for example, detection of a label (16): - none of the cells, then the first (17) of solar cells, then both solar cells (17, 18) at the same time.

3. Encoder device according to claim 2, characterized in that the increment of the following increments defined detection tags (16) at the same time two photocells (17, 18), defined detection tags (16): the second (18) of solar cells, then none of the cells.

4. Encoder on any one of claims 1 to 3, wherein the first item (10) contains an alternating sequence of labels (16) and the absence of labels.

5. Encoder on any one of claims 1 to 3, wherein the encoder is the angular encoder, and the first element is the disc (10), made with the possibility of rotation relative to the second element (11).

6. Encoder device according to claim 4, wherein the encoder is the angular encoder, and the first element is the disc (10), made with the possibility of rotation relative to the second element (11).

7. Encoder on any one of claims 1 to 3, wherein the label (16) is a hole in the first item (10), the second element contains one or two optical emitter, made with the possibility of detecting them one of the photocell (17, 18) detection, and the first element (10) can navigate between the emitter or radiators and solar cells (17, 18).

8. Encoder device according to claim 4, wherein the label (16) is a hole in the first item (10), the second element contains one or two optical emitter, made with the possibility of detecting them one of the photocell (17, 18) detection, and the first element (10) can navigate between the emitter or radiators and solar cells (17, 18).

9. Encoder device according to claim 5, wherein the label (16) is a hole in the first item (10), the second element contains one or two optical emitter, made with the possibility of detecting them one of the photocell (17, 18) detection, and the first element (10) can navigate between the emitter or radiators and solar cells (17, 18).

10. Encoder on item 8, wherein the radiators and solar cells (17, 18) fixed-connected with a bracket (30) U-shape, with a bracket (30) contains two facing each other branches (31, 32), and the emitter or emitters are the one (31) of the branches of the U, and solar cells (17, 18) are in another branch (32) U and the first element (10) moves between the branches (31, 32) U.

11. Encoder to 10, wherein the bracket (30) fixed-is connected to a Board (34) the printed circuit.

12. Encoder on any one of claims 1 to 3, 6, 8-11, wherein contains two second element (30, 34), moving relative to only one of the first item (10), containing at least two labels (16), with each of two second elements (30 of 34) have a pair of photocells (17, 18) detection by one of two marks (16) to provide redundancy detection marks (16).

13. Encoder device according to claim 4, wherein contains two second element (30, 34), moving relative to only one of the first item (10), containing at least two labels (16), with each of two second elements (30 of 34) have a pair of photocells (17, 18) detection by one of two marks (16) to provide redundancy detection marks (16).

14. Encoder device according to claim 7, wherein contains two second element (30, 34), moving relative to only one of the first item (10), containing at least two labels (16), with each of two second elements (30 of 34) have a pair of photocells (17, 18) detection by one of two marks (16) to provide redundancy detection marks (16).

15. Encoder on any one of claims 1 to 3, 6, 8-11, 13, 14, wherein the tool contains (13, 14) for the mechanical detect stable provisions of the two elements (10, 11) relative to each other, and the fact that in the first stable position neither of the two photocells (17, 18) not detect label (16), in the second stable position only one photocell (17, 18) detects the tag (16), and the fact that in the third stable position both photocell (17, 18) detect label (16).

16. Encoder on 12 different because it has tools (13, 14) for the mechanical detect stable provisions of the two elements (10, 11) relative to each other, and the fact that in the first stable position neither of the two photocells (17, 18) not detect label (16), in the second stable position only one photocell (17, 18) detects the tag (16), and the fact that in the third stable position both photocell (17, 18) detect label (16).