Photoelectric key structure of electronic musical instrument and electronic musical instrument

Abstract

The utility model provides a photoelectric key structure of an electronic musical instrument and the electronic musical instrument, comprising a key seat and trigger keys arranged on the key seat, the trigger keys are provided with multistage optical signal reflection mechanisms, the key seat is respectively provided with an optical signal receiving mechanism and a light source mechanism corresponding to each trigger key, the light emitting end of the light source mechanism and the receiving end of the light signal receiving mechanism are respectively arranged corresponding to the light signal reflecting mechanism, and the light source mechanism and the light signal receiving mechanism are respectively connected with a control unit of the electronic musical instrument. According to the utility model, each trigger key is provided with a light source and a light signal receiving mechanism, and a plurality of groups of reflection areas are arranged on the trigger key at intervals, so that when the trigger key is pressed down, a plurality of groups of reflected light signals can be triggered in sequence, and according to the change of the received light reflection signals, the press-down speed of the trigger key can be identified without using a rubber bowl.

Description

Technical Field

[0001] This utility model relates to the field of electronic musical instruments, and in particular to an optoelectronic key structure for an electronic musical instrument and the electronic musical instrument itself. Background Technology

[0002] Key-operated electronic musical instruments, such as electronic keyboards, electric pianos, electric guitars, and electronic drums, generally employ a structure with single, double, or triple dome contacts. The pressing and releasing of the trigger keys are achieved through the on / off switching of multiple sets of contacts, and the pressing speed is detected by the trigger speed of these multiple sets of contacts. Specifically, one to three domes are located below the trigger key, each containing a conductor. Conductive metal contacts are located on the key base corresponding to the bottom of the domes. The height of the conductors inside the different domes varies, thus affecting the number of dome contacts activated when the pressure applied to the trigger key increases, thereby detecting the pressing depth and speed. For example, with three domes, if all three domes are activated, the trigger key is considered pressed; otherwise, it is considered not pressed. Different trigger speeds of the three domes adjust the volume, tone, etc., based on the detected speed.

[0003] Taking an electronic keyboard as an example, for lower-end keyboards, only whether the key is pressed is detected, not the speed. Therefore, only one dome, a conductor, and one set of contacts are used. When the trigger key is pressed, it presses down on the dome, causing the dome to deform until the conductor inside the dome presses onto the two contacts, thus connecting them. Better keyboards use two or three domes for each key. When the key is pressed, because the three conductors are at different heights, the three sets of contacts will connect at different times. Based on the time difference of the connection, the speed at which the key is pressed can be calculated, and the volume, tone, etc., can be changed accordingly.

[0004] However, the rubber cups themselves are rapidly and repeatedly compressed and released during playing, resulting in a limited lifespan and easily changing feel. The conductive contacts at the bottom are prone to poor contact. Therefore, damage or aging of the rubber cups is a common and frequent fault of piano keys. Rubber cups are used as consumables, which is inconvenient and costly to use and replace in practice. Summary of the Invention

[0005] In order to solve the problems existing in the background art, this utility model proposes an optoelectronic key structure for an electronic musical instrument and an electronic musical instrument.

[0006] An optoelectronic key structure for an electronic musical instrument includes a key base and trigger keys disposed on the key base. The trigger keys are provided with multi-level light signal reflection mechanisms. The key base is provided with a light signal receiving mechanism and a light source mechanism corresponding to each trigger key. The light emitting end of the light source mechanism and the receiving end of the light signal receiving mechanism are respectively disposed corresponding to the light signal reflection mechanism. The light source mechanism and the light signal receiving mechanism are respectively connected to the control unit of the electronic musical instrument.

[0007] Based on the above, the optical signal reflection mechanism includes a fixed plate, which is longitudinally arranged at the bottom of one end of the trigger key. Multiple reflective areas are longitudinally arranged on the fixed plate, and light-absorbing areas are arranged between two adjacent reflective areas. Each reflective area is provided with a reflective coating, and the light-absorbing areas are provided with a light-absorbing coating.

[0008] The optical signal reflection mechanism includes a fixed plate, which is vertically positioned at the bottom of one end of the trigger key. A reflective area is vertically positioned on the fixed plate, and a light-absorbing area is positioned below the reflective area. The reflective area and the light-absorbing area are set with a gradient color, or the boundary between the reflective area and the light-absorbing area is set with an inclined shape.

[0009] Based on the above, the light source mechanism includes a light source, a light source branch channel, and a light source channel. The light emitting end of the light source branch channel and the receiving end of the light signal receiving mechanism are respectively set to the light signal reflecting mechanism. Multiple light source branch channels are connected to the light source through the light source channel, and the light source is connected to the control panel of the electronic musical instrument.

[0010] Based on the above, the light source is a light-emitting diode, and the light signal receiving mechanism is a light receiving tube.

[0011] Based on the above, the light source branch channel and the light source channel are both light guides.

[0012] Based on the above, a light-shielding plate is provided on the key base, and a reflective through hole is provided on the light-shielding plate. The reflective area and the ends of the light source mechanism and the light source branch channel are respectively provided on both sides of the reflective through hole.

[0013] Based on the above, the fixing plate is provided with a strip-shaped limiting hole, and the key seat is provided with a corresponding limiting post, with the limiting hole sleeved on the limiting post.

[0014] Based on the above, a tension spring is provided at the other end of the trigger key, and the bottom of the tension spring is located on the key seat.

[0015] An electronic musical instrument includes a key structure that uses the photoelectric key structure of any of the aforementioned electronic musical instruments.

[0016] This invention has substantial features and advancements compared to existing technologies. Specifically, by providing a light source and a light signal receiving mechanism for each trigger key and by setting multiple sets of reflective areas at intervals on the trigger key, one or more sets of emitted light signals can be triggered sequentially when the trigger key is pressed. Based on the changes in the received light reflection signals, the speed of trigger key pressing can be identified using only one AD converter per key. In contrast, existing technologies use multiple rubber domes for each key corresponding to multiple I / O channels, resulting in complex structures and high costs. Furthermore, this application operates in a non-contact manner, eliminating the need for rubber domes, and has the advantages of simple structure, low cost, and long lifespan. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of part of the trigger key of this utility model (tension spring not shown).

[0018] Figure 2 This is a partially enlarged structural diagram of the key socket of this utility model.

[0019] Figure 3 This is a structural schematic diagram of the trigger key and fixing plate of this utility model.

[0020] Figure 4 This is a utility model Figure 1 A schematic diagram of the back structure.

[0021] Figure 5 This is a schematic diagram of the circuit structure of the light source of this utility model.

[0022] Figure 6 This is a schematic diagram of the circuit structure of the optical signal receiving mechanism and control unit of this utility model.

[0023] Figure 7 This is a schematic diagram of the oblique boundary structure of the reflective area and the light-absorbing area of ​​this utility model.

[0024] Figure 8 This is a schematic diagram of the gradient color structure of the reflective and light-absorbing areas of this utility model.

[0025] Explanation of reference numerals in the attached diagram: 1. Trigger key; 2. Fixing plate; 3. Light-shielding plate; 4. Key seat; 5. Reflective through hole; 6. Light signal receiving mechanism; 7. Light source branch channel; 8. Light source channel; 9. Reflective area; 10. Light-absorbing area; 11. Limiting hole; 12. Limiting post. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] There are many types of button-operated electronic musical instruments. This embodiment uses an electronic keyboard and its button structure as an example for explanation: Figures 1-4As shown, an optoelectronic key structure for an electronic musical instrument includes a key base 4 and trigger keys 1 disposed on the key base 4. The trigger keys 1 are piano keys. The trigger keys 1 are provided with a multi-level light signal reflection mechanism. The key base 4 is provided with a light signal receiving mechanism 6 and a light source mechanism for each trigger key 1. The light emitting end of the light source mechanism and the receiving end of the light signal receiving mechanism 6 are respectively disposed for the light signal reflection mechanism. The light source mechanism and the light signal receiving mechanism are respectively connected to the control unit of the electronic musical instrument.

[0028] In this embodiment, the light source mechanism includes a light source, a light source branch channel 7, and a light source channel 8. The key base 4 is provided with the light source branch channel 7 and the light source channel 8. For each trigger key 1, the key base 4 is provided with a light signal receiving mechanism 6 and a light source branch channel 7. The light emitting end of the light source branch channel 7 and the receiving end of the light signal receiving mechanism 6 are respectively provided with light signal reflecting mechanisms. Multiple light source branch channels are connected to the light source mechanism through the light source channel. The light source mechanism and the light signal receiving mechanism 6 are respectively connected to the control unit of the electronic keyboard. In use, multiple trigger keys 1 share a single light source, that is, the light source emits light. After transmission through the light source channel 8 and each light source branch channel 7, the light is emitted through the end of the light source branch channel 7. When trigger key 1 is not pressed, the light signal reflecting mechanism is far away from the light signal receiving mechanism 6 and the emitting end of the light source branch channel 7. At this time, there is no reflected light, and the light signal receiving mechanism 6 cannot receive a signal, therefore there is no detection signal, and it is identified as trigger key 1 not being pressed. When trigger key 1 is pressed, the light signal reflecting mechanism approaches the light signal receiving mechanism 6 and the end of the light source branch channel 7. At this time, the light signal reflecting mechanism reflects the light from the light source to the light signal receiving mechanism 6, and the light signal receiving mechanism 6 receives the light signal. Since each trigger key 1 corresponds to one light signal receiving mechanism 6, the corresponding pressed trigger key 1 can be identified based on the detected reflected light signal. When multiple reflective areas are triggered, it is identified that trigger key 1 has been pressed / triggered. Simultaneously, the speed of the key press is determined based on the interval time of the reflected light signals triggered by the multi-level light signal reflecting mechanism, and different functions such as volume / timbre changes are output according to the different key press speeds. In other embodiments, the light source mechanism can also be a light source, that is, each key corresponds to a light source, and the working principle is the same as above, which will not be repeated here.

[0029] Specifically, the light signal reflection mechanism includes a fixing plate 2, which is vertically positioned at the bottom of one end of the trigger key 1. Multiple reflective areas 9 are vertically arranged on the fixing plate 2, and a light-absorbing area 10 is positioned between adjacent reflective areas 9. Each reflective area 9 contains a reflective coating, and each light-absorbing area 10 contains a light-absorbing coating. In this embodiment, the reflective coating is white reflective paint, and the light-absorbing coating is non-reflective or low-reflective black paint. It is worth noting that reflectivity and non-reflectivity are relative; the light-absorbing area does not reflect absolutely no light, but the difference between the two is significant enough to be easily identified and distinguished. In the initial state, i.e., the horizontal state, the light signal receiving mechanism 6 is close to the lower black light-absorbing area, at which point there is no light or only a small amount of reflected light signal. In the fully pressed state, the light signal receiving mechanism 6 is close to the uppermost white reflective area, at which point the reflected light signal is stronger. In a preferred embodiment, there is only one reflective area and one light-absorbing area, with the light-absorbing area positioned below the reflective area. The boundary between the reflective and light-absorbing areas is inclined, such as... Figure 7 As shown, during the key press process, when the reflective and light-absorbing areas switch, the AD sampling of the reflected light signal received by the light signal receiving mechanism 6 is high-speed continuous sampling. The voltage change is linearly related to the key press distance, thus obtaining higher accuracy in key press speed. In other embodiments, the reflective and light-absorbing areas are set with a gradient color, such as... Figure 8 As shown, the principle is the same as in the oblique boundary embodiment.

[0030] In this embodiment, as Figure 5 and Figure 6As shown in the diagram (only two paths are shown for the light source and two paths for the light signal receiving mechanism 6, but multiple paths are actually provided as needed), the light source is a light-emitting diode (LED), and chip U1A is the control unit of the electronic keyboard itself (this embodiment only uses an STM32F103C8T6 MCU as an example for explanation, and is not limited to this), and the light signal receiving mechanism 6 is a light receiving tube, specifically an Everlight IRPT26-21C series ball-head 1206 surface-mount transmitter-receiver tube. The control unit U1A controls the switching on and off of transistors Q2 and Q3 by outputting high and low levels, thereby controlling the switching on and off of the LED and the power supply, and thus controlling the operation of the LED light source. When there is no reflected light or the reflected light is low, the reverse current of the photosensitive receiving tube is very small, and the pins of control unit U1A receive a high level from the AD0 and / or AD1 terminals, indicating that no key is pressed; when there is reflected light, the reverse current of the photosensitive receiving tube increases rapidly, and the pins of control unit U1A receive a low level from the AD0 and / or AD1 terminals, indicating that a key is pressed. After the light receiver detects the reflected light, it converts it into an electrical signal through a common photoelectric conversion circuit and sends it to the control unit of the electronic keyboard to perform corresponding function outputs, such as outputting different volumes according to the pressing speed of trigger key 1. Light source branch channel 7 and light source channel 8 are both light guides, and in this embodiment, they are made of transparent plastic. In reality, light source branch channel 7 and light source channel 8 are integrated, with multiple trigger keys sharing a single light source, reducing the use of LEDs and lowering cost and power consumption.

[0031] Preferably, a light-shielding plate 3 is provided on the key base 4, and the light-shielding plate 3 is disposed close to the fixing plate 2. The light-shielding plate 3 is provided with a reflective through hole 5. The ends of the light signal receiving mechanism 6 and the light source branch channel 7 are disposed on one side of the reflective through hole 5, and the fixing plate 2 is disposed on the other side of the reflective through hole 5. This makes the light signal receiving mechanism 6, the ends of the light source branch channel 7, and the reflective area 9 when the trigger key 1 is pressed within a small space, avoiding light interference from the outside world and adjacent keys.

[0032] In reality, the trigger key 1 is set on the key seat using a common structure. In this embodiment, the bottom of the trigger key 1 near the other end is provided with a V-shaped protrusion, and the key seat 4 is provided with a corresponding matching V-shaped groove. The other end of the trigger key 1 is provided with a tension spring (not shown in the figure), and the bottom of the tension spring is set on the key seat 4. The fixing plate 2 is provided with a strip-shaped limiting hole 11, and the key seat 4 is provided with a corresponding limiting post 12. The limiting hole 11 is sleeved on the limiting post 12. Under normal conditions, the trigger key 1 remains horizontal under the tension of the tension spring and the cooperation of the limiting hole 11 and the limiting post 12. When the trigger key 1 is pressed, the limiting hole 11 moves downward relative to the limiting post 12, and the length of the strip-shaped side of the limiting hole 11 limits the maximum stroke of the trigger key 1. At this time, the tension spring is in a further stretched state. After the trigger key 1 is released, the trigger key 1 returns to the horizontal position under the tension of the tension spring. In other embodiments, the tension spring can also be replaced by a counterweight, such as a cylindrical metal block, to serve to reset the trigger key 1.

[0033] This embodiment also provides an electronic musical instrument, including a key structure, wherein the key structure uses the photoelectric key structure of the electronic musical instrument described above.

[0034] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A photoelectric key structure for an electronic musical instrument, comprising a key base and a trigger key disposed on the key base, characterized in that: The trigger key is equipped with a multi-level light signal reflection mechanism. The key base is equipped with a light signal receiving mechanism and a light source mechanism for each trigger key. The light emitting end of the light source mechanism and the receiving end of the light signal receiving mechanism are respectively set to the light signal reflection mechanism. The light source mechanism and the light signal receiving mechanism are respectively connected to the control unit of the electronic musical instrument.

2. The photoelectric key structure of the electronic musical instrument according to claim 1, characterized in that: The optical signal reflection mechanism includes a fixed plate, which is vertically arranged at the bottom of one end of the trigger key. Multiple reflective areas are vertically arranged on the fixed plate, and light-absorbing areas are arranged between two adjacent reflective areas. Each reflective area is provided with a reflective coating, and the light-absorbing areas are provided with a light-absorbing coating.

3. The photoelectric key structure of the electronic musical instrument according to claim 1, characterized in that: The optical signal reflection mechanism includes a fixed plate, which is vertically positioned at the bottom of one end of the trigger key. A reflective area is vertically positioned on the fixed plate, and a light-absorbing area is positioned below the reflective area. The reflective area and the light-absorbing area are set with a gradient color, or the boundary between the reflective area and the light-absorbing area is set with an inclined shape.

4. The photoelectric key structure of the electronic musical instrument according to claim 2, characterized in that: The light source mechanism includes a light source, light source branch channels, and a light source channel. The light emitting end of the light source branch channel and the receiving end of the light signal receiving mechanism are respectively set to the light signal reflecting mechanism. Multiple light source branch channels are connected to the light source through the light source channel, and the light source is connected to the control unit of the electronic musical instrument.

5. The photoelectric key structure of the electronic musical instrument according to claim 4, characterized in that: The light source is a light-emitting diode, and the light signal receiving mechanism is a light receiving tube.

6. The photoelectric key structure of the electronic musical instrument according to claim 1, characterized in that: The light source branch channel and the light source channel are both light guides.

7. The photoelectric key structure of the electronic musical instrument according to claim 2, characterized in that: A light-shielding plate is provided on the key base, and a reflective through hole is provided on the light-shielding plate. The reflective area and the ends of the light signal receiving mechanism and the light source branch channel are respectively set on both sides of the reflective through hole.

8. The photoelectric key structure of the electronic musical instrument according to claim 2, characterized in that: The fixing plate is provided with a strip-shaped limiting hole, and the key seat is provided with a corresponding limiting post, with the limiting hole sleeved on the limiting post.

9. The photoelectric key structure of the electronic musical instrument according to claim 8, characterized in that: The other end of the trigger key is equipped with a tension spring, and the bottom of the tension spring is mounted on the key base.

10. An electronic musical instrument, comprising a key structure, characterized in that: The key structure uses the photoelectric key structure of the electronic musical instrument according to any one of claims 1-9.

Images