Detector array for position sensor and connection method of detection units of detector array

Abstract

The invention relates to a detector array for a position sensor and a connection method of detection units of the detector array, and the detector array employs first pitches and second pitches between adjacent detection units to be alternately distributed on the detector array. Parts with the same electric connection mode corresponding to different light intensity distribution periods among the detection units are connected in the chip, and then different combined wiring is carried out outside the chip according to different application occasions, so that optical signal processing for different light intensity distribution periods only needs to be reconnected on a circuit board in the later period of application. Optical signals with different light intensity distribution periods can be compatibly detected, so that the cost is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of position sensors, and in particular relates to a detector array for a position sensor and a connection method of a detection unit thereof. Background Art

[0002] Position sensors, especially grating-based position sensors, are usually formed by scanning stripes on a standard grating. As the distance of the light emitted by the light source changes, the signal is modulated by the standard grating and the scanning grating (or there may be no scanning grating), generating a photoelectric signal that changes with the position. This includes a grating self-imaging system based on the Talbot effect or a system of multi-grating combined imaging ("An encoder apparatus", publication number: EP3347681B1). This displacement measurement device also includes a plurality of detection units, which are usually divided into 4 groups. The phase differences corresponding to the 4 groups of detection units are 0°, 90°, 180°, and 270°. Finally, differential processing is performed to obtain two sinusoidal signals with a phase difference of 90 degrees.

[0003] In the "Photodiode Array, Photodiode Detection System and Optical Encoder" (Announcement No.: CN101403626) disclosed in the Chinese Patent Gazette, a photodiode array arrangement method is disclosed. This arrangement method directly receives the light intensity distribution of grating imaging, and different groups receive signals of different phases. While receiving small-period signals, the spacing between photodiodes is not very small, thereby reducing the difficulty of manufacturing.

[0004] This technology has solved the problem of detector manufacturing to a certain extent, but different optical signals will still use different detectors, and detectors with different optical signal periods are not compatible. For example, if there is a detector that can receive optical signals with a period of 20 microns, it cannot be directly used for optical signals with a period of 40 microns. The new optical signal requires redesigning and manufacturing the detector, which will undoubtedly increase the cost and cycle of design and production, and increase the risk of errors. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a detector array for a position sensor and a connection method of its detection unit that is compatible with optical signals with different light intensity distribution periods.

[0006] In order to solve the above technical problems, the detector array for position sensor of the present invention includes M detection units, M is an integer multiple of 16; there is a first pitch D1 and a second pitch D2 between adjacent detection units, the first pitch D1 and the second pitch D2 are alternately distributed on the detector array, and D2=2.5D1.

[0007] The first pitch D1 and the light intensity distribution period T of the optical signal have the following relationship: T=k×D1, k=2 or 4.

[0008] The detection unit is CCD, CMOS, or silicon photocell.

[0009] The connection method of the detection units in the above-mentioned detector array for the position sensor is as follows: first, the M detection units are divided into 8 groups, the detection units in each group are phase-related and electrically connected together inside the chip, and 8 signal lines are led out; then, according to the relationship between the light intensity distribution period T of the optical signal and the first pitch D1, the 8 signal lines are combined outside the chip into 4 output signal lines with output phases of 0°, 90°, 180°, and 270° respectively.

[0010] Assume that the detection units are numbered 16*i+1, 16*i+2, ..., 16*i+16 in sequence, i=0, 1, 2, 3..., N-1; 16*(N-1)+16=M; inside the chip, the detection units numbered 16*i+1 and 16*i+6 are electrically connected to lead out the H signal line, the detection units numbered 16*i+3 and 16*i+8 are electrically connected to lead out the G signal line, the detection units numbered 16*i+5 and 16*i+10 are electrically connected to lead out the F signal line, The detection units numbered 16*i+7 and 16*i+12 are electrically connected to lead out the E signal line, the detection units numbered 16*i+2 and 16*i+13 are electrically connected to lead out the D signal line, the detection units numbered 16*i+9 and 16*i+14 are electrically connected to lead out the C signal line, the detection units numbered 16*i+4 and 16*i+15 are electrically connected to lead out the B signal line, and the detection units numbered 16*i+11 and 16*i+16 are electrically connected to lead out the A signal line.

[0011] For the case of T=2×D1, the C signal line and the H signal line are electrically connected outside the chip to form an output signal line with an absolute output phase of 0°, the A signal line and the G signal line are electrically connected to form an output signal line with an absolute output phase of 270°, the F signal line and the D signal line are electrically connected to form an output signal line with an absolute output phase of 180°, and the E signal line and the B signal line are electrically connected to form an output signal line with an absolute output phase of 90°.

[0012] For the case of T=4×D1, the B signal line and the H signal line are electrically connected outside the chip to form an output signal line with a relative output phase of 0°, the F signal line and the G signal line are electrically connected to form an output signal line with a relative output phase of 270°, the E signal line and the C signal line are electrically connected to form an output signal line with a relative output phase of 180°, and the A signal line and the D signal line are electrically connected to form an output signal line with a relative output phase of 90°.

[0013] The present invention adopts the alternating distribution of the first pitch and the second pitch between adjacent detection units on the detector array, connects the parts with the same electrical connection method corresponding to different light intensity distribution periods inside the chip, and then performs different combination wiring outside the chip according to different application scenarios. In this way, the optical signal processing for different light intensity distribution periods only needs to be reconnected on the circuit board in the later stage of application, which is compatible with the detection of optical signals with different light intensity distribution periods, thereby reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of a chip internal connection method of a detector array and a detection unit thereof for a position sensor of the present invention.

[0015] Figure 2 yes Figure 1 Schematic diagram of the internal chip of the detection unit and the external connection method in the first case.

[0016] Figure 3 yes Figure 1 Schematic diagram of the internal chip of the detection unit and the external connection method in the second case. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0018] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood in specific circumstances.

[0019] like Figure 1As shown, the detector array for position sensor of the present invention includes M detection units 100, M is an integer multiple of 16; the detection units are numbered in sequence as 16*i+1, 16*i+2, ..., 16*i+16, i=0, 1, 2, 3..., N-1, that is, 16*(N-1)+16=M; for the optical signal outputted in two phases, there is a first pitch D1 and a second pitch D2 between adjacent detection units, and the first pitch D1 and the second pitch D2 are alternately distributed on the detector array; D2=2.5D1. The detection unit 100 can be one of CCD (Charge-coupled Device), CMOS (Complementary Metal Oxide Semiconductor) or silicon photocell; the pitch here refers to the distance between the centers of adjacent detection units.

[0020] Suppose the intensity distribution period of the optical signal is T. The intensity distribution here refers to the distribution along the measurement direction of the position sensor. The intensity distribution period T can be, for example, 20 microns, 40 microns or any other size. The pitch arrangement is to detect different phases of the optical signal. The detection units that receive the same phase are connected. The usual connection method is to connect inside the chip (integrated chip) or on the circuit board. When the intensity distribution period T is relatively small, an integrated chip is usually used, but this type of chip can usually only process optical signals with one intensity distribution period.

[0021] The detector array for position sensors and the connection method of the detection units thereof of the present invention are compatible with two optical signals with different light intensity distribution periods, where the light intensity distribution period is T=k×D1, k=2 or 4.

[0022] If the optical signal is simplified to a sinusoidal signal with a light intensity distribution period of T, the signal output by each detection unit can be expressed as I=A×cos(X×2π / T+Δ)+A0, where X represents the displacement coordinate (i.e., the shift measurement data), A and A0 are constants independent of the shift measurement data, Δ is the phase, and T is the light intensity distribution period.

[0023] like Figure 1 As shown, the connection method of the detection unit is to first divide the detection unit into 8 groups, and the detection units in each group are phase-related and electrically connected together inside the chip to lead out 8 signal lines; then, according to the relationship between the light intensity distribution period T of the optical signal and the first pitch D1, the 8 signal lines are combined outside the chip into 4 output signal lines that can output phases of 0°, 90°, 180°, and 270° respectively. The 4 output signals can output two sine and cosine signals with a phase difference of 90 degrees through a differential amplifier, thereby obtaining shift measurement data. For the two cases of light intensity distribution period T=k×D1, k=2 or 4, the output signal phase of each detection unit is shown in Table 1.

[0024] Table 1

[0025] Signal line Detection unit number Δ(T=2*D1), unit:° Δ(T=4*D1), unit:° A 16*i+11 or 16*i+16 270 135 B 16*i+4 or 16*i+15 90 45 C 16*i+9 or 16*i+14 0 180 D 16*i+2 or 16*i+13 180 90 E 16*i+7 or 16*i+12 90 225 F 16*i+5 or 16*i+10 180 270 G 16*i+3 or 16*i+8 270 315 H 16*i+1 or 16*i+6 0 0

[0026] Inside the chip, the detection units numbered 16*i+1 and 16*i+6 are electrically connected to lead out the H signal line, the detection units numbered 16*i+3 and 16*i+8 are electrically connected to lead out the G signal line, the detection units numbered 16*i+5 and 16*i+10 are electrically connected to lead out the F signal line, the detection units numbered 16*i+7 and 16*i+12 are electrically connected to lead out the E signal line, the detection units numbered 16*i+2 and 16*i+13 are electrically connected to lead out the D signal line, the detection units numbered 16*i+9 and 16*i+14 are electrically connected to lead out the C signal line, the detection units numbered 16*i+4 and 16*i+15 are electrically connected to lead out the B signal line, the detection units numbered 16*i+11 and 16*i+16 are electrically connected to lead out the A signal line.

[0027] like Figure 2 As shown, for the case of T=2×D1, the C signal line is electrically connected to the H signal line outside the chip, with an output phase of 0°, the A signal line is electrically connected to the G signal line, with an output phase of 270°, the F signal line is electrically connected to the D signal line, with an output phase of 180°, and the E signal line is electrically connected to the B signal line, with an output phase of 90°.

[0028] like Figure 3 As shown, for the case of T=2×D1, the B signal line is electrically connected to the H signal line outside the chip, and the output absolute phase is 22.5°, and the relative phase is 0°. The F signal line is electrically connected to the G signal line, and the output absolute phase is 292.5°, and the relative phase is 270°. The E signal line is electrically connected to the C signal line, and the output absolute phase is 202.5, and the relative phase is 180°. The A signal line is electrically connected to the D signal line, and the output absolute phase is 112.5°, and the relative phase is 90°.

[0029] The present invention is different from similar position sensor arrays in that:

[0030] The signal processing method used by the existing position sensor array groups the signals output by each detection unit and obtains 4 signals with different phases on the chip, but it is not compatible with optical signals with different light intensity distribution periods. The present invention divides the signal processing output by each detection unit into two steps: inside the chip and outside the chip. In the first step, the common connection part of the optical signals with different light intensity distribution periods is set inside the chip. In the second step, different wiring is performed outside the chip according to different light intensity distribution periods based on the first step; in this way, the optical signals with different light intensity distribution periods T only need to be rewired on the circuit board in the later stage of application.

[0031] To summarize, the present invention is not limited to the above-mentioned embodiments. For example, the number of detector units is not 4N (N is an integer), but can be 3N detector units based on 3-phase output, or even other KN detection units (K-phase output). The same method can be used to obtain a detector array of a position sensor compatible with optical signals of different light intensity distribution periods and a connection method of its detection units. For example, when the pitch D1 and the pitch D2 are the same (the adjacent detector units have the same phase difference), the chip can still be divided into 8 groups within the chip, and 4 groups can be obtained by connecting them outside the chip. For example, more groups can be used to achieve compatibility with more different periods. If divided into 16 groups, the connection methods corresponding to 3 different periods can be output, and so on.

Claims

1. A detector array for a position sensor, characterized in that: The detector array includes M detection units, where M is an integer multiple of 16; there is a first pitch D1 and a second pitch D2 between adjacent detection units, the first pitch D1 and the second pitch D2 are alternately distributed on the detector array, and D2=2.5D1.

2. The detector array for a position sensor according to claim 1, characterized in that: The first pitch D1 and the light intensity distribution period T of the optical signal have the following relationship: T=k×D1, k=2 or 4.

3. The detector array for a position sensor according to claim 1, characterized in that: The detection unit is CCD, CMOS, or silicon photocell.

4. A method for connecting detection units in a detector array for a position sensor as claimed in claim 1, characterized in that: First, the M detection units are divided into 8 groups. The detection units in each group are phase-related and electrically connected inside the chip, leading to a total of 8 signal lines. Then, according to the relationship between the light intensity distribution period T of the optical signal and the first pitch D1, the 8 signal lines are combined outside the chip into 4 output signal lines with output phases of 0°, 90°, 180°, and 270° respectively.

5. The method for connecting detection units in a detector array for a position sensor according to claim 4, characterized in that: Assume that the detection units are numbered 16*i+1, 16*i+2, ..., 16*i+16 in sequence, i=0, 1, 2, 3..., N-1; 16*(N-1)+16=M; inside the chip, the detection units numbered 16*i+1 and 16*i+6 are electrically connected to lead out the H signal line, the detection units numbered 16*i+3 and 16*i+8 are electrically connected to lead out the G signal line, the detection units numbered 16*i+5 and 16*i+10 are electrically connected to lead out the F signal line, The detection units numbered 16*i+7 and 16*i+12 are electrically connected to lead out the E signal line, the detection units numbered 16*i+2 and 16*i+13 are electrically connected to lead out the D signal line, the detection units numbered 16*i+9 and 16*i+14 are electrically connected to lead out the C signal line, the detection units numbered 16*i+4 and 16*i+15 are electrically connected to lead out the B signal line, and the detection units numbered 16*i+11 and 16*i+16 are electrically connected to lead out the A signal line.

6. The method for connecting detection units in a detector array for a position sensor according to claim 5, characterized in that: For the case of T=2×D1, the C signal line and the H signal line are electrically connected outside the chip to form an output signal line with an absolute output phase of 0°, the A signal line and the G signal line are electrically connected to form an output signal line with an absolute output phase of 270°, the F signal line and the D signal line are electrically connected to form an output signal line with an absolute output phase of 180°, and the E signal line and the B signal line are electrically connected to form an output signal line with an absolute output phase of 90°.

7. The method for connecting detection units in a detector array of a position sensor according to claim 5, characterized in that: For the case of T=4×D1, the B signal line and the H signal line are electrically connected outside the chip to form an output signal line with a relative output phase of 0°, the F signal line and the G signal line are electrically connected to form an output signal line with a relative output phase of 270°, the E signal line and the C signal line are electrically connected to form an output signal line with a relative output phase of 180°, and the A signal line and the D signal line are electrically connected to form an output signal line with a relative output phase of 90°.

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