Subtraction processing photoelectric conversion circuit

Abstract

The utility model discloses a subtraction processing photoelectric conversion circuit and a subtraction processing photoelectric conversion circuit. The subtraction processing photoelectric conversion circuit comprises a first channel conversion circuit, a second channel conversion circuit and a processor, the output end of the first channel conversion circuit is connected to the positive electrode of a first subtraction circuit and the negative electrode of a second subtraction circuit through a first emitter follower. The output end of the second channel conversion circuit is connected to the negative electrode of the first subtraction circuit and the positive electrode of the second subtraction circuit through a second emitter follower. The subtraction circuit and the conversion circuit are connected and matched to counteract dark current, so that the problem that the signal transmission accuracy of the circuit is damaged by a noise source is effectively avoided.

Description

Technical Field

[0001] The utility model relates to the field of photoelectric conversion, in particular to a subtraction processing photoelectric conversion circuit. Background Art

[0002] In the prior art, photoelectric conversion generally converts one optical signal into one channel, and multiple optical signals use a multiplexer circuit. Since the photosensitive device is made of semiconductor materials, it will be affected by temperature, humidity, and even light. Even if it is not affected by light, the device itself will have dark current. At the same time, the circuit characteristics will also have the existence of a DC bias component, which will cause the converted signal to be unreal and inaccurate. Due to the existence of noise sources, the final data will be complicated. Therefore, a photoelectric conversion channel is designed that can form a dark current offset and avoid noise sources based on a multiplexer circuit. Utility Model Content

[0003] The purpose of this section is to summarize some aspects of the embodiments of the utility model and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract of the specification and the name of the utility model of this application to avoid blurring the purpose of this section, the abstract of the specification and the name of the utility model, and such simplifications or omissions cannot be used to limit the scope of the utility model.

[0004] In view of the above and / or existing problems in the prior art, the photosensitive device is made of semiconductor materials and will be affected by temperature, humidity, and even light. Even when not affected by light, the device itself will have dark current characteristics. At the same time, the circuit characteristics will also have the existence of a DC bias component, which will cause the converted signal to be unrealistic and inaccurate. The present utility model is proposed.

[0005] Therefore, the technical problem to be solved by the present invention is to design a photoelectric conversion channel that can form a dark current offset and avoid noise sources on the basis of a multiplexer circuit.

[0006] In order to solve the above technical problems, the utility model provides the following technical solutions: a subtraction processing photoelectric conversion circuit, comprising a first channel conversion circuit, a second channel conversion circuit, and a processor;

[0007] The output end of the first channel conversion circuit is connected to the positive electrode of the first subtraction circuit and the negative electrode of the second subtraction circuit through the first emitter follower;

[0008] The output end of the second channel conversion circuit is connected to the cathode of the first subtraction circuit and the anode of the second subtraction circuit through a second emitter follower.

[0009] As a preferred solution of the subtraction processing photoelectric conversion circuit described in the utility model, wherein: a first light emitting diode is provided in the first channel conversion circuit, the first light emitting diode is connected to the first operational amplifier, and its output voltage U1 passes through the first emitter follower and enters the positive electrode of the first subtraction circuit and the negative electrode of the second subtraction circuit.

[0010] As a preferred solution of the subtraction processing photoelectric conversion circuit described in the utility model, wherein: a second light emitting diode is provided in the second channel conversion circuit, the second light emitting diode is connected to the second operational amplifier, and its output voltage U2 passes through the second emitter follower and enters the negative electrode of the first subtraction circuit and the positive electrode of the second subtraction circuit.

[0011] As a preferred solution of the subtraction processing photoelectric conversion circuit of the utility model, wherein: the first emitter follower forms a voltage signal isolation between the first channel conversion circuit and the first subtraction circuit;

[0012] The second emitter follower forms voltage signal isolation between the second channel conversion circuit and the second subtraction circuit.

[0013] As a preferred solution of the subtraction processing photoelectric conversion circuit of the utility model, wherein: the first channel conversion circuit, the first emitter follower, and the first subtraction circuit constitute a first photoelectric conversion channel;

[0014] The second channel conversion circuit, the second emitter follower, and the second subtraction circuit constitute a second photoelectric conversion channel.

[0015] As a preferred solution of the subtraction processing photoelectric conversion circuit of the utility model, wherein: the output voltage of the first subtraction circuit is connected to a sampling port of the processor as the final output voltage U3 of the first photoelectric conversion channel;

[0016] The output voltage of the second subtraction circuit is connected to the two-way sampling port of the processor as the final output voltage U4 of the second photoelectric conversion channel.

[0017] As a preferred solution of the subtraction processing photoelectric conversion circuit of the utility model, wherein: the first photoelectric conversion channel and the second photoelectric conversion channel adopt a cyclic processing working mode;

[0018] When the first light emitting diode is affected by the light source and generates an output voltage U1, the second light emitting diode is not affected by the light source and does not generate U2;

[0019] When the second light emitting diode is affected by the light source, it generates an output voltage U2, while the first light emitting diode is not affected by the light source and does not generate U1.

[0020] As a preferred solution of the subtraction processing photoelectric conversion circuit described in the utility model, in which: in the case of no subtraction circuit:

[0021] When in the first photoelectric conversion channel: U1+one-pass noise source=U3, two-pass noise source=U4;

[0022] In the second photoelectric conversion channel: when U2+two-pass noise source=U4, one-pass noise source=U3;

[0023] The electrical signals of the one-pass noise source and the two-pass noise source are equal.

[0024] The beneficial effect of the utility model is that the dark current is offset by connecting and cooperating with the subtraction circuit and the conversion circuit. This method effectively avoids the problem that the noise source damages the accuracy of circuit signal transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following briefly introduces the drawings required for the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0026] Figure 1 A circuit connection diagram of a subtraction processing photoelectric conversion circuit according to an embodiment of the utility model;

[0027] Figure 2 A schematic diagram of circuit connection of a subtraction processing photoelectric conversion circuit according to an embodiment of the utility model when U1 is illuminated;

[0028] Figure 3 A schematic diagram of circuit connection of a subtraction processing photoelectric conversion circuit according to an embodiment of the utility model when U2 is illuminated; DETAILED DESCRIPTION

[0029] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0030] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0031] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general proportion, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0032] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0033] Example 1

[0034] Reference Figure 1 , this embodiment provides a subtraction processing photoelectric conversion circuit, including a first channel conversion circuit 100, which is the starting point of one of the multiplexer circuits, a second channel conversion circuit 200 which is the starting point of the other channel, and a processor 300 which is the end of the two output voltages;

[0035] The output end of the first channel conversion circuit 100 is connected to the positive electrode of the first subtraction circuit 102 and the negative electrode of the second subtraction circuit 202 through the first emitter follower 101, forming a multi-path basic current splitting effect, thereby also making the electrical signal stably output in both paths;

[0036] The output end of the second channel conversion circuit 200 is connected to the negative electrode of the first subtraction circuit 102 and the positive electrode of the second subtraction circuit 202 through the second emitter follower 201. The same as above, and the main function of the two emitter followers 101 is to ensure that the connection process between the conversion circuit and the subtraction circuit will not be affected by the load, thereby forming an isolation level buffer effect and reducing the impact of direct connection between circuits.

[0037] In detail, a first light emitting diode 100a is provided in the first channel conversion circuit 100, and the first light emitting diode 100a is connected to the first operational amplifier 100b, and its output voltage U1 passes through the first emitter follower 101 and enters the positive electrode of the first subtraction circuit 102 and the negative electrode of the second subtraction circuit 202. Therefore, the output voltage of the first channel conversion circuit 100 comes from the first light emitting diode 100a, and is adjusted by the first operational amplifier 100b to form the final U1. In the entire conversion circuit, a conversion resistor and a conversion capacitor are also connected in parallel. U1, as an output voltage, will be affected by dark current by default, thereby causing the influence of noise sources.

[0038] Furthermore, a second light emitting diode 200a is provided in the second channel conversion circuit 200, and the second light emitting diode 200a is connected to the second op amp 200b, and its output voltage U2 passes through the second emitter follower 201 and enters the negative electrode of the first subtraction circuit 102 and the positive electrode of the second subtraction circuit 202. Similarly to the above, U2, as an output voltage, is also affected by the dark current. Both conversion circuits have noise sources, which will be offset by adding a subtraction circuit later.

[0039] Example 2

[0040] Reference Figure 1~2 , which is the second embodiment of the utility model, and this embodiment is based on the previous embodiment, and is different from the previous embodiment in that: the first emitter follower 101 forms a voltage signal isolation between the first channel conversion circuit 100 and the first subtraction circuit 102, that is, the role of the emitter follower;

[0041] The second emitter follower 201 forms voltage signal isolation between the second channel conversion circuit 200 and the second subtraction circuit 202, similar to the above.

[0042] Furthermore, the first channel conversion circuit 100, the first emitter follower 101, and the first subtraction circuit 102 form a first photoelectric conversion channel A. The entire first photoelectric conversion channel A is a complete conversion circuit of the multiplexer circuit. The first subtraction circuit 102 is used to adjust U1 output by the first channel conversion circuit 100 to offset the noise source in the circuit.

[0043] Similarly, the second channel conversion circuit 200, the second emitter follower 201, and the second subtraction circuit 202 constitute the second photoelectric conversion channel B, and the noise source is also offset by the second subtraction circuit 202. The adoption of the subtraction circuit in the multiplexing circuit requires the above-mentioned positive and negative cross-shunt connection.

[0044] Furthermore, the output voltage of the first subtraction circuit 102 is connected to a sampling port 301 of the processor 300 as the final output voltage U3 of the first photoelectric conversion channel A. The final output voltage is the voltage output after being adjusted by the subtraction circuit.

[0045] Similarly, the output voltage of the second subtraction circuit 202 is connected to the two-way sampling port 302 of the processor 300 as the final output voltage U4 of the second photoelectric conversion channel B.

[0046] Example 3

[0047] Reference Figures 1 to 3 , which is the third embodiment of the utility model, and this embodiment provides a subtraction processing photoelectric conversion circuit. This embodiment is based on the previous embodiment, and the difference from the previous embodiment is that:

[0048] The first photoelectric conversion channel A and the second photoelectric conversion channel B adopt a cyclic processing working mode, that is, when one conversion channel has an output voltage, the other conversion channel is not powered;

[0049] Furthermore, when the first light diode 100a is affected by the light source and generates an output voltage U1, the second light diode 200a is not affected by the light source and does not generate U2. This principle is controlled by the lighting equipment in front of the two light diodes, which is also in line with the working idea of ​​​​patrol processing;

[0050] Similarly, when the second light emitting diode 200a is affected by the light source and generates an output voltage U2, the first light emitting diode 100a is not affected by the light source and does not generate U1.

[0051] In detail, the circuit design of the circuit processing is given. The two interconnected conversion circuits cooperate with the subtraction circuit at the end to form an ingenious processing effect. It is easy to understand. If the subtraction circuit at the end is cancelled, the voltage in the two photoelectric conversion channels is as follows:

[0052] ① When in the first photoelectric conversion channel A: U1+one-channel noise source = U3, the two-channel noise source = U4;

[0053] ② When in the second photoelectric conversion channel B: U2+two-channel noise source = U4, one-channel noise source = U3;

[0054] The electrical signals of the one-pass noise source and the two-pass noise source are equal.

[0055] In logic ①, it is obvious that the first photoelectric conversion channel A is in a state with output voltage and noise source. Based on the circuit processing principle, the second photoelectric conversion channel B has no output voltage at this time, and only has a noise source generated by the existence of dark current. The same is true for logic ② in reverse.

[0056] Furthermore, if the two conversion circuits are designed through the subtraction circuit at the end, it will form:

[0057] ③ In the illumination of the first photoelectric conversion channel A: U3=U1+one-channel noise source-U4 (two-channel noise source);

[0058] ④ In the illumination of the second photoelectric conversion channel B: U4 = U2 + two-channel noise source - U3 (one-channel noise source);

[0059] That is, the equation for ③ is U3=U1, and the equation for ④ is U4=U2;

[0060] This also achieves what our technical solution wants to achieve: the effect of eliminating the noise source.

[0061] Importantly, it should be noted that the construction and arrangement of the present application shown in a number of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, and parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of the element may be inverted or otherwise changed, and the nature or number or position of the discrete element may be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present utility model. The order or sequence of any process or method steps may be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure described herein that performs the function, and is not only structurally equivalent but also an equivalent structure. Without departing from the scope of the present invention, other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the present invention is not limited to a specific embodiment, but extends to various modifications that still fall within the scope of the appended claims.

[0062] Additionally, in order to provide a concise description of example embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.

[0063] It will be appreciated that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will be a routine task of design, fabrication, and production for those of ordinary skill having the benefit of this disclosure without undue experimentation.

[0064] It should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A subtraction processing photoelectric conversion circuit, characterized in that: include, A first channel conversion circuit (100), a second channel conversion circuit (200), and a processor (300); The output end of the first channel conversion circuit (100) is connected to the positive electrode of the first subtraction circuit (102) and the negative electrode of the second subtraction circuit (202) through the first emitter follower (101); The output end of the second channel conversion circuit (200) is connected to the negative electrode of the first subtraction circuit (102) and the positive electrode of the second subtraction circuit (202) through the second emitter follower (201).

2. The subtraction processing photoelectric conversion circuit according to claim 1, characterized in that: The first channel conversion circuit (100) is provided with a first light emitting diode (100a), the first light emitting diode (100a) is connected to the first operational amplifier (100b), and its output voltage U1 passes through the first emitter follower (101) and enters the positive electrode of the first subtraction circuit (102) and the negative electrode of the second subtraction circuit (202).

3. The subtraction processing photoelectric conversion circuit according to claim 2, characterized in that: The second channel conversion circuit (200) is provided with a second light emitting diode (200a), the second light emitting diode (200a) is connected to the second operational amplifier (200b), and its output voltage U2 passes through the second emitter follower (201) and enters the negative electrode of the first subtraction circuit (102) and the positive electrode of the second subtraction circuit (202).

4. The subtraction processing photoelectric conversion circuit according to claim 3, characterized in that: The first emitter follower (101) forms voltage signal isolation between the first channel conversion circuit (100) and the first subtraction circuit (102); The second emitter follower (201) forms voltage signal isolation between the second channel conversion circuit (200) and the second subtraction circuit (202).

5. The subtraction processing photoelectric conversion circuit according to claim 4, characterized in that: The first channel conversion circuit (100), the first emitter follower (101), and the first subtraction circuit (102) form a first photoelectric conversion channel (A); The second channel conversion circuit (200), the second emitter follower (201), and the second subtraction circuit (202) form a second photoelectric conversion channel (B).

6. The subtraction processing photoelectric conversion circuit according to claim 5, characterized in that: The output voltage of the first subtraction circuit (102) is connected to a sampling port (301) of the processor (300) as the final output voltage U3 of the first photoelectric conversion channel (A); The output voltage of the second subtraction circuit (202) is connected to the two-way sampling port (302) of the processor (300) as the final output voltage U4 of the second photoelectric conversion channel (B).

7. The subtraction processing photoelectric conversion circuit according to claim 6, characterized in that: The first photoelectric conversion channel (A) and the second photoelectric conversion channel (B) adopt a cyclic processing working mode; When the first light emitting diode (100a) is affected by the light source and generates an output voltage U1, the second light emitting diode (200a) is not affected by the light source and does not generate U2; When the second light emitting diode (200a) is affected by the light source and generates an output voltage U2, the first light emitting diode (100a) is not affected by the light source and does not generate U1.

8. The subtraction processing photoelectric conversion circuit according to claim 7, characterized in that: Without subtraction circuit: When in the first photoelectric conversion channel (A): U1+one-pass noise source=U3, two-pass noise source=U4; In the second photoelectric conversion channel (B): when U2+two-pass noise source=U4, one-pass noise source=U3; The electrical signals of the one-pass noise source and the two-pass noise source are equal.

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