Optical path structure

Abstract

The present invention discloses an optical path structure, which includes a cavity with one end open. At the other end of the cavity relative to the opening, there is a first through hole or a first notch, and a first LED. The light emitted by the first LED enters the cavity through the first through hole or the first notch. On the side of the cavity, there are also a second through hole or a second notch, and a second LED. The light emitted by the second LED enters the cavity through the second through hole or the second notch. A beam splitter or a dichroic mirror is also arranged in the cavity. The light emitted by the first LED directly passes through the beam splitter or the dichroic mirror and exits from the opening of the cavity. The light emitted by the second LED is reflected by the beam splitter or the dichroic mirror and merged with the light emitted by the first LED, wherein the optical paths of the light emitted by the first LED and the second LED reaching the beam splitter or the dichroic mirror are the same. The present invention realizes the consistency of the optical path and the fusion of light through the design of a compact cavity structure.

Description

Technical Field

[0001] The present invention relates to an optical path structure, in particular to an optical path structure in a sensor. Background Art

[0002] In a chromaticity sensor or a turbidity sensor, an optical path is required to fuse two light beams of different wavelengths. However, in the prior art, during the process of fusing light beams, for different light sources, a combination of multiple prisms is required to adjust the light transmission direction so as to fuse the light beams into the same optical path. However, this design causes the optical path lengths experienced by the light beams emitted from different light sources to be different before fusion, thereby affecting the effect of light beam fusion. Moreover, this design uses relatively more prisms and / or lenses, making the optical path structure complex.

[0003] In some other designs, optical fibers are used to transmit the light beams emitted from different light sources. For example, a Y-shaped optical fiber is used to fuse and output the light beams of two light sources. The introduction of the optical fiber solves the problem of different optical path lengths, but reduces the efficiency of light beam fusion, and the optical fiber is fragile and expensive. Also, due to the requirement of a compact structure for the sensor, the installation of the optical fiber is difficult and it is not suitable for extensive use in sensors. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the defects in the prior art that the optical path structure of the sensor is too complex and the different optical path lengths result in low light beam fusion efficiency, and to provide a new optical path structure to achieve consistent optical path lengths and light beam fusion through a compact cavity structure design.

[0005] The present invention solves the above technical problem by the following technical solutions:

[0006] The present invention provides an optical path structure, characterized in that the structure includes a cavity with one end open. At the other end of the cavity relative to the opening, there is provided a first through hole or a first notch, and a first LED. The light emitted by the first LED enters the cavity through the first through hole or the first notch. A second through hole or a second notch, and a second LED are also provided on the side surface of the cavity. The light emitted by the second LED enters the cavity through the second through hole or the second notch. A beam splitter or a dichroic mirror is further provided in the cavity. The light emitted by the first LED directly passes through the beam splitter or the dichroic mirror and exits from the opening of the cavity. The light emitted by the second LED is reflected by the beam splitter or the dichroic mirror and fuses with the light emitted by the first LED and then exits from the opening of the cavity, wherein the optical path lengths of the light emitted by the first LED and the second LED reaching the beam splitter or the dichroic mirror are the same.

[0007] A beam splitter or dichroic mirror that can combine the light from two different directions into a single beam of light. In the present invention, this feature of the beam splitter or dichroic mirror is utilized to combine the light rays of different LEDs, thereby simplifying the optical path structure in the sensor.

[0008] Among them, the light rays enter the beam splitter or dichroic mirror perpendicularly to each other and are combined and output. Therefore, at one end and the side of the cavity, the LED light rays are constructed into a structure that enters the beam splitter or dichroic mirror perpendicularly to each other, and this setting method is also easy to achieve the control of the optical path, and further achieve the same optical path of the two LED light rays before combining the light.

[0009] Preferably, the optical path structure further includes a photodiode.

[0010] The side of the cavity also has a third through hole, and the photodiode is disposed at the through hole.

[0011] Or,

[0012] The photodiode is disposed at the second notch and has a set distance from the second LED.

[0013] Preferably, a light shielding member is disposed between the photodiode and the second LED, so that the light emitted by the second LED cannot directly irradiate the photosensitive surface of the photodiode.

[0014] The photodiode is used to receive the light rays from the first LED passing through the beam splitter or dichroic mirror or the light rays from the second LED reflected by the beam splitter or dichroic mirror and propagating to the side wall of the cavity in the cavity.

[0015] The present invention uses a photodiode to detect the light intensity in the cavity, and further adjusts the light intensity of the LED or is used to correct the measurement result of the sensor.

[0016] Preferably, the first LED and the second LED are respectively LED circuit boards.

[0017] Preferably, the second LED and the photodiode are integrated on the same LED circuit board.

[0018] Preferably, at the opening of the cavity, a lens or a lens group is further provided, and the lens or the lens group converts the combined light rays into parallel light or convergent light.

[0019] In the present invention, a lens is further used to adjust the form of the combined light beam.

[0020] Preferably, the lens or the lens group is detachably disposed at the opening.

[0021] Preferably, the lens or lens group is disposed on a connecting member having threads, and the connecting member is screwed to the opening.

[0022] Preferably, the first LED and the second LED can emit light simultaneously or at different times. The wavelengths of the light emitted by the first LED and the second LED are different. When this optical path structure is used in a sensor, the advantage of emitting light at different times is that the signals detected subsequently correspond to different wavelengths at different times, and no special device is required to distinguish different wavelengths.

[0023] Preferably, the optical path structure is applied to a sensor, especially a chromaticity sensor or a turbidity sensor or a chromaticity-turbidity integrated sensor.

[0024] The positive and progressive effects of the present invention are as follows:

[0025] By utilizing the characteristics of a beam splitter or a dichroic mirror, the present invention realizes a consistent optical path and light fusion, and at the same time, realizes a compact cavity structure design in the sensor.

[0026] Compared with the traditional design of multiple groups of prisms or optical fibers, the optical path design of the present invention has higher reliability, higher light efficiency, lower cost, and is convenient for processing and adjustment.

[0027] In the cavity design of the present invention, light detection is further integrated to intelligently adjust the light intensity of the light source or intelligently correct the measurement results of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic cross-sectional view of the optical path structure of Embodiment 1 of the present invention.

[0029] Figure 2 It is a schematic cross-sectional view of the optical path structure of Embodiment 2 of the present invention.

[0030] Figure 3 It is a schematic cross-sectional view of the optical path structure of a modified example of the present invention.

[0031] Figure 4 It is a schematic cross-sectional view of the optical path structure of Embodiment 3 of the present invention.

[0032] Figure 5 It is a schematic cross-sectional view of the optical path structure of another embodiment of the present invention.

[0033] Reference Signs

[0034] Cavity 1

[0035] Through holes 21, 22

[0036] Notches 21’, 22’

[0037] Red LED 31

[0038] Blue LED 32

[0039] LED boards 31’, 32’

[0040] Photodiode 33

[0041] Light shielding member 34

[0042] Beam splitter 4

[0043] Dichroic mirror 4’

[0044] Lens 5

[0045] Threaded connector 6 Detailed implementation mode

[0046] The present invention will be further described below by way of embodiments, but the present invention is not limited to the scope of the described embodiments.

[0047] The present invention utilizes the characteristics of a beam splitter or a dichroic mirror to combine the light rays emitted in two different directions, especially the light rays perpendicular to each other, from different LEDs, thereby simplifying the optical path structure for combining light in the sensor and also achieving a compact optical path structure.

[0048] The implementation manner of the present invention will be illustrated by the following-described embodiments.

[0049] Embodiment 1

[0050] As Figure 1 shown, in this embodiment, the optical path structure includes a cuboid cavity 1 with one end open and a through hole 21 provided on the end surface of the other end. The red LED 31 is arranged at the through hole 21, and the light rays emitted by the LED 31 are emitted through the through hole 21 in the direction of the opening of the cavity 1.

[0051] A through hole 22 is provided on the side surface S1 of the four side surfaces of the cavity 1, and the blue LED 32 is arranged at the through hole 22. The light rays emitted by the LED 32 are emitted through the through hole 22 in the direction of the side surface S2.

[0052] A dichroic mirror 4 is arranged in the cavity 1 as Figure 1 shown. In this embodiment, the dichroic mirror 4 can allow the red light emitted by the LED 31 to directly pass through the dichroic mirror 4, but reflect the blue light emitted by the LED 32 at 90°. At this time, the directly passing red light and the 90°-reflected blue light are combined, and the combined light rays are emitted from the opening of the cavity 1.

[0053] Moreover, in this embodiment, the dichroic mirror 4 is arranged such that the optical path of the red light emitted by the LED 31 to reach the beam splitter is the same as the optical path of the blue light emitted by the LED 32 to reach the beam splitter, which facilitates subsequent collimation using a lens or a lens group and achieves higher light efficiency.

[0054] In a variant of this embodiment, the number of sides of the cavity is 5, 8, or even 17. As long as the optical paths of the blue light and the red light can be made perpendicular, the number and shape of the sides can be set arbitrarily, not limited to the cube or prism structure of this embodiment.

[0055] Embodiment 2

[0056] As Figure 2 shown, the cavity 1 in this embodiment is a cylinder. One end of the cavity 1 is open, and a strip-shaped notch 21' is provided on the end surface of the other end. The LED board 31' covers the notch 21', and the light emitted by the LED board 31' is emitted through the notch 21' in the direction of the opening of the cavity 1.

[0057] A strip-shaped notch 22' is provided on the side surface of the cavity 1. The LED board 32' covers the notch 22', and the light emitted by the LED board 32' is emitted through the notch 22' to the other side of the cavity opposite to the notch 22'.

[0058] In this embodiment, a photodiode 33 is further provided on the LED board 32'. The photodiode 33 faces the notch 22' to collect the light intensity in the cavity.

[0059] Moreover, a light shielding member 34 is provided between the second LED 22 and the photodiode 33, so that the light emitted by the second LED 22 cannot directly irradiate the photosensitive surface of the photodiode 33, thereby avoiding the photodiode from detecting an incorrect optical signal. In the cavity 1, as Figure 2 shown, the beam splitter 4' is arranged. In this embodiment, the beam splitter 4' allows approximately half of the light emitted by the LED board 31' to directly pass through the beam splitter 4', but reflects approximately half of the light emitted by the LED board 32' at 90°. At this time, the directly passing light and the 90° reflected light are combined, and the combined light is emitted from the opening of the cavity 1.

[0060] Moreover, in this embodiment, the arrangement of the beam splitter 4' also makes the optical path of the light emitted by the LED board 31' to reach the beam splitter the same as the optical path of the light emitted by the LED board 32' to reach the beam splitter, which facilitates subsequent collimation using a lens or a lens group and achieves higher light efficiency.

[0061] In a variant of this embodiment, as Figure 3As shown, the side of the cavity 1 also has an independent through hole for setting a photodiode to collect the intensity of the light in the cavity. At this time, the side wall of the cavity between the through hole and the through hole or notch for setting the second LED serves as a light blocking member to block the light emitted by the second LED from directly irradiating the photodiode. In another variant, the side wall of the cavity between the through hole and the through hole or notch for setting the second LED is thickened or a light blocking member is added to the side wall of the cavity, thereby improving the light shielding effect.

[0062] In another variant, a notch is also provided on the side of the cavity 1, and the circuit board where the photodiode is located covers the notch to collect the intensity of the light in the cavity.

[0063] Embodiment 3

[0064] As Figure 4 shown, the difference between this embodiment and Embodiment 2 is that at the opening of the cavity 1 in this embodiment, a lens 5 is provided, and the lens 5 collimates and converts the combined light beam into parallel light or performs light concentration.

[0065] In a variant of this embodiment, the lens can be a lens group to convert the combined light beam into parallel light or perform light concentration.

[0066] As Figure 5 shown in another embodiment, the lens 5 is embedded on a threaded connector 6, and the threaded connector matches the thread at the opening of the cavity 1, and the threaded connector 6 can be screwed and fixed at the opening.

[0067] In another embodiment of this embodiment, the lens or lens group is embedded in the opening of the cavity through a snap, and can be manually or with the aid of tools removed from the opening of the cavity. Using the snap can more conveniently fix the lens in the opening of the cavity, and the snap can also meet the requirements for lens removal.

[0068] Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that these are only examples, and the protection scope of the present invention is defined by the appended claims. Without departing from the principles and essence of the present invention, those skilled in the art can make various changes or modifications to these embodiments, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. An optical path structure, It is characterized in that The optical path structure is used for a colorimetric sensor or a turbidity sensor, and the structure includes a cavity with an opening at one end, and the other end of the cavity relative to the opening is provided with a first through hole or a first notch, and a first LED, and the light emitted by the first LED is emitted into the cavity through the first through hole or the first notch, and the side of the cavity is also provided with a second through hole or a second notch, and a second LED, and the light emitted by the second LED is emitted into the cavity through the second through hole or the second notch, and a beam splitter or a two-way color mirror is also provided in the cavity, and the light emitted by the first LED directly passes through the beam splitter or the two-way color mirror and is emitted from the opening of the cavity, and the light emitted by the second LED is reflected by the beam splitter or the two-way color mirror and merged with the light emitted by the first LED, wherein the optical path of the light emitted by the first LED and the second LED to reach the beam splitter or the two-way color mirror is the same; The optical path structure further includes a photodiode, the photodiode faces the notch to collect the light intensity in the cavity, the side of the cavity further has a third through hole, the photodiode is arranged at the through hole; or, the photodiode is arranged at the second notch and has a set distance from the second LED; A light blocking member is arranged between the photodiode and the second LED to prevent the light emitted by the second LED from directly irradiating the photodiode.

2. The optical path structure according to claim 1, It is characterized in that The first LED and the second LED are circuit boards equipped with LEDs respectively.

3. The optical path structure as claimed in claim 2, It is characterized in that The second LED and the photodiode are integrated on the same circuit board.

4. The optical path structure according to claim 1, It is characterized in that The first LED and the second LED emit light simultaneously or in different time periods.

5. The optical path structure according to claim 1, It is characterized in that A lens or a lens group is also arranged at the opening of the cavity, and the lens or the lens group converts the fused light into parallel light or focused light.

6. The optical path structure as claimed in claim 5, It is characterized in that The lens or lens group is detachably arranged at the opening.

7. The optical path structure according to claim 6, It is characterized in that The lens or lens group is arranged on a connecting member with threads, and the connecting member is screwed to the opening.

8. The optical path structure according to any one of claims 1 to 7, It is characterized in that The optical path structure is applied to a colorimetric sensor or a turbidity sensor or a colorimetric and turbidity two-in-one sensor.

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