KR20200134358A - Test system using midi program for digital piano - Google Patents

Abstract

A keying test system of a digital piano comprises: an automatic keying unit vertically keying each key of a digital piano having a plurality of keying switches for each key at a set keying speed and keying depth; a transfer unit transferring the automatic keying unit to a position where each of the keys is arranged; and a test unit receiving sound source information generated when each key is automatically keyed as a MIDI file through a musical instrument digital interface (MIDI) protocol, and visually displaying a keying status of each key based on the information in the MIDI file. Therefore, the keying test system can visually display a keying status of each key.

Description

Digital piano keying test system using MIDI program {TEST SYSTEM USING MIDI PROGRAM FOR DIGITAL PIANO}

The present invention relates to a digital piano key test system, and to a technology capable of improving the accuracy of a keyboard test.

A digital piano is an instrument that generates an electronic sound by the operation of an electric switch, unlike a general piano that produces sound by hitting the internal strings by physical and mechanical action when a key is pressed. A keyboard instrument that reproduces the sound almost similar to that of a normal piano. to be. Since digital pianos use digital sounds stored in hardware, they do not need to be tuned and can be used interchangeably with other devices, and they can produce various types of sounds different from those of ordinary pianos, as well as sounds of various instruments such as violins, drums, and saxophones. Due to its built-in strength, it is widely used in fields such as education, learning, practice, and hobbies.

The digital piano uses a method of outputting a corresponding sound when switching is detected by mounting a key switch at the bottom of each key. Meanwhile, in general, a keying switch electrically connects two contacts, and a difference in switching timing between the two contacts is determined and the sound level is adjusted according to the difference. For example, a small difference in switching timing means that a key is pressed at a high speed, so the sound is relatively loud compared to a large difference in switching timing. Recently, a technology for expressing sounds corresponding to more various keystroke types is used by using two or more contact points. However, as the number of such contacts increases, various types of sound can be expressed, but the number of items to be tested during the manufacturing process increases. Conventionally, a skilled tester has performed a test based on experience while adjusting the keying speed and keying depth, but this has a disadvantage that it is difficult to clearly test numerically and it takes a long time to test.

In other words, the quality level of a keyboard of a conventional digital piano and a digital piano including the keyboard is determined by a constraint condition in which a performance deviation is determined by a physical combination. Therefore, in determining the excellent quality, it is necessary to adjust the strength of the keyboard to the target value, and for the already assembled keys, the weight, operating range, and contact point signal generation time are measured only indirectly by a person.

The present invention has been proposed to solve the above technical problem, and the sound source information generated when each key is automatically keyed is transmitted as a MIDI file through the MIDI (Musical Instrument Digital Interface) protocol, and based on the information of the MIDI file. It provides a digital piano keystroke test system that can visually display the keystroke status of each key.

According to an embodiment of the present invention, an automatic keying unit for vertically keying each key of a digital piano having a plurality of keying switches for each key at a set keying speed and keying depth, and an automatic keying unit transferred to a position where each key is arranged A test that visually displays the keystroke status of each key based on the information in the MIDI file and receives the sound source information generated when each key is automatically keyed and transmitted as a MIDI file through the MIDI (Musical Instrument Digital Interface) protocol. A digital piano keystroke test system including parts is provided.

In addition, the test unit included in the present invention, when each key is automatically keyed, a control unit for storing the switching timing of the plurality of keying switches of the key, setting the keying speed and the keying depth, and each keying depth Including a display unit that displays whether or not the plurality of key switches of each key are switched according to the key, and displays the difference between the reference switching time according to the key key speed and the switching time of the plurality of key keys of each key by key speed. It is characterized.

In addition, the display unit included in the present invention is characterized in that the difference between the reference pressure and the measured pressure of each keyboard is aligned and displayed.

In addition, the control unit included in the present invention is characterized in that a plurality of keys are controlled to be automatically keyed one by one in the order in which they are arranged, or one or more keys are controlled to be keyed simultaneously.

In addition, the automatic keying unit included in the present invention includes a first finger bar for automatically keying a white key among a plurality of keys, a second finger bar for automatically keying a black key among a plurality of keys, and a key key of a white key and a black key. It characterized in that it comprises a pressure sensor for measuring the pressure.

The digital piano keying test system according to the present invention receives sound source information generated when each key is automatically keyed as a MIDI file through the MIDI (Musical Instrument Digital Interface) protocol, and the keying state of each key based on the information of the MIDI file. Can be displayed visually.

Through the MIDI program, the output values and corresponding data sent from the keyboard to the digital piano are communicated through USB MIDI Protocol, and the existing test process is improved by providing the keyboard strength and data necessary for adjustment work in the condition of the completed keyboard and digital piano. can do.

The keyboard of a digital piano is composed of assembling and combining of various parts such as metal, plastic, PCB, rubber, wood, etc., so there is a deviation according to the assembling property.In the past, in order to verify the performance of a digital piano keyboard, the weight and operating range , Although the timing at which the signal occurs at the PCB contact point of the keyboard was measured indirectly, in the present invention, the MIDI signal generated through the MIDI program can be easily visually verified by the test unit. The test unit can be composed of a general computer, mobile phone, smart phone, and smart pad.

That is, the signal generated from the contact point is transmitted to the test unit (PC) through USB MIDI communication, and the signal is directly checked through the MIDI program, so that the problem of the keyboard assembly can be verified in the state of the finished product.

For reference, the digital piano can be divided into a keyboard module and a reproduction module that reproduces a MIDI signal transmitted from the keyboard module. In general, a keyboard module, a reproduction module, and a frame are combined to complete a digital piano. Therefore, it is possible to measure the digital piano keyboard in the state of parts using the MIDI program installed in the test unit, and it is a program that can perform verification on the keyboard part even in the digital piano in the state of a finished product. It is a product of parts, finished products, and A/S. It can be used for repair.

In addition, the key can be automatically keyed at a constant keying speed at a set keying speed, which increases test accuracy and test speed.

In addition, it is possible to automatically check whether or not multiple contacts are switched by key depth.

In addition, since it is possible to test while keying more than one key at the same time, the test speed is increased.

As a result, it is possible to statisticalize test data for each stroke speed and for each stroke depth, and based on this statistics, it is possible to develop a product that can reduce the defect rate of the product.

1 is a configuration diagram of a digital piano key gun test system according to an embodiment of the present invention
2 is a cross-sectional view showing a plurality of key switch portions of the keyboard
3 is a flow chart showing a test process of the digital piano key gun test system according to an embodiment of the present invention
4 is a diagram showing the results of an automatic keying test
5 is a configuration diagram showing a detailed module of a MIDI program installed in the test unit
6 is a diagram showing a screen displayed by a MIDI program installed in a test unit
7 is a schematic structural diagram of a MIDI file
8 is a structure diagram of a header chunk of a MIDI file
9 is a structure diagram of a track chunk of a MIDI file

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings in order to describe in detail enough to allow those of ordinary skill in the art to easily implement the technical idea of the present invention.

1 is a block diagram of a digital piano key gun test system 1 according to an embodiment of the present invention.

The digital piano keynote test system 1 according to the present embodiment includes only a simple configuration for clearly explaining the technical idea to be proposed.

Referring to FIG. 1, the digital piano keying test system 1 includes a keyboard module 100, a mounting part 200, an automatic keying part 300, a transfer part 400, and a test part 700. It consists of including. At this time, the test unit 700 includes a control unit 500 and a display unit 600, and a MIDI program is installed.

A detailed configuration and main operation of the digital piano keystroke test system 1 configured as described above will be described as follows.

The digital piano can be divided into a keyboard module and a reproduction module that reproduces MIDI signals transmitted from the keyboard module. In general, a keyboard module, a reproduction module, and a frame are combined to complete a digital piano.

In this embodiment, the test unit 700 serves as a playback module and at the same time receives sound source information generated when each key of the keyboard module is automatically keyed as a MIDI file through a MIDI (Musical Instrument Digital Interface) protocol. It is configured to visually display the keying state of each key based on the information of. MIDI data may be transmitted between the keyboard module and the test unit 700 through wired communication or wireless communication.

The mounting part 200 is fixed by mounting the keyboard module 100 of the digital piano. The keyboard module 100 is completed as a digital piano in the form of a finished product by mounting an external frame when it is determined as good after being tested.

A plurality of key switches are disposed under each key of the key module 100. Accordingly, the timing of switching of the plurality of key switches is adjusted in response to the speed and depth of pressing the keyboard, and the volume or height of the sound is adjusted in consideration of the switching timing.

Therefore, as the number of keystrokes assigned to each key increases, that is, as the number of contacts increases, faster and more detailed performance becomes possible. Also, as the number of contact points increases, phenomena such as sound splashing decrease.

The automatic keying unit 300 is disposed above the mounting unit 200, and keys keys in a vertical direction from the top of the key module 100 mounted on the mounting unit 200.

At this time, the automatic keying unit 300 keys the key at the keying speed and keying depth set by the control unit 500. In general, the test is conducted at four speeds (40vv, 60vv, 90vv, 127vv) during the test process. The keystroke speed and keystroke depth can be set in various ways depending on the design value of the keyboard.

The automatic keying unit 300 includes a finger bar for keying keys at a set speed and depth using a hydraulic or electric motor method.

Depending on the embodiment, the number of finger bars may be adjusted. When two finger bars are provided, the test may be conducted by dividing the application into a first finger bar for automatically keying a white key among a plurality of keys, and a second finger bar for automatically keying a black key among a plurality of keys.

On the other hand, the automatic keying unit 300 may be configured to further include a pressure sensor for measuring keying pressure of a white key and a black key. That is, when a keyboard is pressed with a pressure higher than or equal to the reference value during the test, the touch feeling and sound reproduction of the keyboard may be poor, and thus the defective keyboard may be selected using a pressure sensor in the test process.

The number of finger bars and pressure sensors may be appropriately adjusted in consideration of the number of keys, test speed, and test device manufacturing cost. In addition, when the finger bars of the automatic keying unit 300 key a plurality of keys, keying may be performed sequentially one by one in the order in which the keys are arranged, or keying may be performed by alternating white and black keys. The keying method of the automatic keying unit 300 is controlled by the setting of the control unit 500.

The transfer unit 400 transfers the finger bar of the automatic keying unit 300 to the top of the keyboard module 100 under the control of the control unit 500. That is, the transfer unit 400 adjusts the position of the automatic keying unit 300 so that the finger bar can be accurately positioned above each key.

The position of the transfer unit 400 may be adjusted according to the control of the control unit 500. When the automatic keying test of all keys is completed, the transfer unit 400 is controlled to return to the initial position.

The control unit 500 may be directly connected to the keyboard module 100, or may be connected through a compatible interface card or equipment. The control unit 500 may be a general computer.

The controller 500 sets a keying speed and a keying depth when each key of the keyboard module 100 is automatically keyed. In addition, during the keying operation, the switching timings of the plurality of keying switches of the corresponding key are stored, and the test data is processed and transmitted to the display unit 600. In addition, the control unit 500 may process data on the measured pressure of the pressure sensor and transmit it to the display unit 600.

The display unit 600 displays whether a plurality of keying switches of each key are switched according to each keying depth. That is, in the case of a keyboard having three contacts, three contacts must be sequentially switched according to the keying depth, and whether each contact is switched according to the keying depth is arranged and displayed.

In addition, the display unit 600 sorts and displays the difference between the reference switching time according to each keying speed and the switching time of a plurality of keying switches of each key by keying speed. In addition, when the pressure sensor is provided, the display unit 600 may align and display the difference between the reference pressure and the measured pressure of each keyboard.

2 is a cross-sectional view showing a plurality of key switch portions of the keyboard.

Referring to FIG. 2, contacts 21, 22, and 23 of a plurality of key switches are disposed under each key of the digital piano. In the case of keying a keyboard, the pressing plates 11, 12, 13 of a plurality of keying switches at the top apply pressure to the contacts 21, 22 and 23 at the bottom in order to perform the switching operation.

Looking in more detail, the first pressing plate 11, the second pressing plate 12, and the third pressing plate 13 at the top are the first contact point 21, the second contact point 22, and the third contact point 23 at the bottom. It is placed in a position opposite to.

When the keyboard is pressed to a certain depth, the first pressing plate 11 and the first contact point 21 contact each other, thereby performing a first switching operation. Next, when the keyboard is pressed deeper, the second pressing plate 12 and the second contact point 22 are brought into contact with each other to perform a second switching operation. Next, when the keyboard is pressed even more deeply, the third pressing plate 13 and the third contact point 23 are brought into contact with each other, thereby performing a third switching operation.

The digital piano controls sound reproduction by the keystroke through a first switching point in which the above-described first switching operation is performed, a second switching point in which the second switching operation is performed, and a third switching point in which the third switching operation is performed.

That is, when the keyboard is keyed, considering the time difference (Δt1) between the first and second switching times and the difference (Δt2) between the second and third switching times, how quickly the keyboard is Since it can be determined whether or not it is pressed, the keyboard module 100 determines the difference (Δt1, Δt2) between the switching timings and reproduces the sound of the corresponding key.

For reference, as the number of contacts assigned to the keyboard increases, it is possible to perform playing with a playing technique very similar to that of an acoustic piano. The control unit 500 of the automatic keying test apparatus 1 according to the present invention stores the difference (Δt1, Δt2) of the above-described switching timing, compares it with the reference switching timing, and sorts these results to the display unit 600. Will be transmitted.

For reference, the key switch illustrated in this embodiment is configured to perform a switching operation using a physical contact method. However, according to the embodiment, a key switch configured in a non-contact switching method using a solenoid coil or the like may be used.

3 is a flow chart showing a test process of the digital piano key gun test system according to an embodiment of the present invention.

Referring to FIG. 3, a test process of the digital piano key gun test system 1 according to an embodiment of the present invention will be described as follows.

The test method of a digital piano having a plurality of key keys for each key includes a step of automatically keying (S10), a step of storing the keying result (S20), and a step of displaying the result (S30).

The automatic keying step (S10) is a process of automatically keying a plurality of keys at a set keying speed and keying depth.

In addition, the storing of the keying result (S20) is a process of storing the switching times of the plurality of keying switches of the corresponding key to be keyed.

In addition, the step of displaying the result (S30) includes whether to switch a plurality of key switches of each key according to each key key depth, a reference switching time according to each key key speed, and when a plurality of key key switches of each key are switched. It is a display process by sorting the difference of by hitting speed.

Meanwhile, a detailed look at the process (S10) of automatically keying a plurality of keys is as follows.

First, when testing a plurality of keys, the keystroke speed and keystroke depth for keystroke must be set in advance (S11).

Next, when the keying speed and keying depth are set, the plurality of keys are automatically keyed at the set keying speed and keying depth (S12). In this case, a plurality of keys may be sequentially keyed one by one in the order of arrangement, or white and black keys may be keyed alternately. Also, more than one key may be keyed simultaneously. In addition, the pressure of the keyboard can be automatically measured when hitting, and the pressure measurement result can be displayed.

Next, when keying a plurality of keys in sequence, a process of determining whether all keys have been keyed (S13) is performed, and if all keys are not keyed, the key is continuously moved to the position of the unkeyed key (S14, S15). The keying process is repeated. If the keying of all the keys has been performed, the result stored in the step of storing the keying result (S20) is sorted and displayed (S30).

Item importance Before improvement Development target value Assessment Methods ARM SETS
STROKE
(Velocity:60) WHITE KEY 1st ON 25 - 4.5 1st on measurement 2nd ON - 8.0 2nd on measurement BLACK KEY 1st ON 25 - 4.5 1st on measurement 3rd ON - 7.0 2nd on measurement ARM SETS
VELOCITY
(stroke:9mm) WHITE KEY vv: 40 12.5 - 40 GMS standard vv: 60 12.5 - 60 GMS standard vv: 90 12.5 - 90 GMS standard vv:127 12.5 - 127 GMS standard Inspection time 1 SET inspection 20min 5min Time measurement

Table 1 is a table showing the performance when a two-contact keyboard is tested at four keystrokes and two keystrokes depths.

Referring to Table 1, after setting the keying depth of 9mm, keying at each keying speed (40vv, 60vv, 90vv, 127vv), setting the keying speed of 60vv, and adjusting the keying depth to adjust the 1st and 2nd keystrokes. It can be seen that the total test time is 5 minutes when testing whether the secondary contact is switched. It can be seen that the test time is shortened compared to 20 minutes, which is the time when the expert manually tested.

4 is a diagram showing the results of an automatic keying test.

Referring to FIG. 4, the results obtained when all keys are automatically keyed at a keying speed of 60vv are graphically shown. If the test data is statisticalized in this way, the defect rate of the product can be reduced based on this statistics, and it can be reflected in improving the performance of the product in the future.

5 is a block diagram showing a detailed module of a MIDI program installed in a test unit.

-MIDI Event Processing Module

Receives a MIDI event from an external MIDI device, converts it into a human-recognizable MIDI signal, and converts it into data for character display of each MIDI signal on the screen.

-OS Wavetable MIDI output

Click the keyboard on the screen to output MIDI and sound through the internal OS sound source (Wavetable). In 3,4 Byte Event, it is classified by signal and converted into text that can be recognized on the screen.

-GUI input event processing

The function for branch processing of each MIDI signal and note event is displayed on the screen by converting strings and converting graph coordinate positions.

-OS Event Callback

The MIDI Event on the OS is received from the Callback Event and stored in the Cycling Buffer (buffer that is stored in the data queue according to the processing size), and stored for use in an external processor (Background).

-MIDI Event branch processing

Each event is processed in the data queue received from the MIDI program and reflected in the GUI.

6 is a diagram showing a screen displayed by a MIDI program installed in a test unit.

The menu displayed on the screen will be described with reference to FIG. 6 as follows.

1. MIDI Input device on PC

Devices that send MIDI signals to the program: keyboard, digital piano, portable piano

2. MIDI Output device on PC

A device that includes a sound source and sound source for outputting sound through signals received from the program: PC OS built-in Wavetable MIDI, external sound source module, digital piano

3. Re-recognition setting when connecting a new device

4. Display the key signal value in Time Graph

: MIDI Velocity

5. MIDI Event Data display

: Display device operation status and signal

6. MIDI Event Data display

: Display the device operation status and the original data (Raw Data) of the generated signal

7. Keyboard scale display

: Note value display

8. Keyboard strength

: Velocity display

9. Keyboard speed bar graph display

: Graph Tool to check the uniformity from the 1st key to the 88th key

10. Keystroke position indication

: Display the key position where the signal is generated by the key

7 is a schematic structural diagram of a MIDI file, FIG. 8 is a structure diagram of a header chunk of a MIDI file, and FIG. 9 is a structure diagram of a track chunk of a MIDI file.

The structure of a MIDI file basically consists of a series of blocks called chunks, as shown in FIGS. 7 to 9.

A MIDI file consists of a continuous string in units of bytes or words, and the part beginning with "MThd" or "MTrk" as ASCII characters is the beginning of the chunk.

The above-described chunk is largely divided into two parts: a header chunk and a track chunk. The header chunk part appears only once in a MIDI file and contains information about the time resolution of the MIDI file. This time resolution is used as the basic unit of time for the MIDI device to play the file. Track chunks are chunks that contain all information about each note, and contain information such as pitch, loudness, length, and tone. This information is contained in an event in the MIDI file. An event refers to'all actions related to the player playing or operating an instrument' and consists of a MIDI event, a system exclusive event, and a meta event.

The digital piano keying test system according to the present invention receives sound source information generated when each key is automatically keyed as a MIDI file through the MIDI (Musical Instrument Digital Interface) protocol, and the keying state of each key based on the information of the MIDI file. Can be displayed visually.

Through the MIDI program, the output values and corresponding data sent from the keyboard to the digital piano are communicated through USB MIDI Protocol, and the existing test process is improved by providing the keyboard strength and data necessary for adjustment work in the condition of the completed keyboard and digital piano. can do.

The keyboard of a digital piano is composed of assembling and combining of various parts such as metal, plastic, PCB, rubber, wood, etc., so there is a deviation according to the assembling property.In the past, in order to verify the performance of a digital piano keyboard, the weight and operating range , Although the timing at which the signal occurs at the PCB contact point of the keyboard was measured indirectly, in the present invention, the MIDI signal generated through the MIDI program can be easily visually verified by the test unit. The test unit can be composed of a general computer, mobile phone, smart phone, and smart pad.

That is, the signal generated from the contact point is transmitted to the test unit (PC) through USB MIDI communication, and the signal is directly checked through the MIDI program, so that the problem of the keyboard assembly can be verified in the state of the finished product.

For reference, the digital piano can be divided into a keyboard module and a reproduction module that reproduces a MIDI signal transmitted from the keyboard module. In general, a keyboard module, a reproduction module, and a frame are combined to complete a digital piano. Therefore, it is possible to measure the digital piano keyboard in the state of parts using the MIDI program installed in the test unit, and it is a program that can perform verification on the keyboard part even in the digital piano in the state of a finished product. It is a product of parts, finished products, and A/S. It can be used for repair. In addition, it can be applied to programs specialized for digital pianos or electronic musical instruments produced with MIDI-based technology, and can be extended to other fields of MIDI-based electronic instruments.

As such, those skilled in the art to which the present invention pertains will be able to understand that the present invention can be implemented in other specific forms without changing the technical spirit or essential features thereof. Therefore, the embodiments described above are illustrative in all respects and should be understood as non-limiting. The scope of the present invention is indicated by the claims to be described later rather than the detailed description, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention. do.

100: keyboard module
200: mounting part
300: automatic keying unit
400: transfer unit
500: control unit
600: display unit
700: test section
11, 12, 13: pressure plate
21, 22, 23: contact

Claims (5)

An automatic keying unit for vertically keying each key of a digital piano having a plurality of keying switches for each key at a set keying speed and keying depth;
A transfer unit for transferring the automatic keying unit to a position where each of the keys is arranged; And
A test unit that receives sound source information generated when each key is automatically keyed as a MIDI file through a MIDI (Musical Instrument Digital Interface) protocol, and visually displays the keying state of each key based on the information of the MIDI file;
Digital piano key gun test system comprising a.
The method of claim 1,
The test unit,
When each key is automatically keyed, a control unit configured to store switching timings of a plurality of keying switches of a corresponding key, and setting the keying speed and the keying depth; And
It displays whether or not a plurality of keystrokes of each key are switched according to each keystroke depth, and displays the difference between the reference switching timing according to each keystroke speed and the switching timings of the plurality of keystroke switches by keystroke speed. Digital piano key gun test system comprising a; display unit.
The method of claim 2,
The display unit,
A digital piano tagging test system, characterized in that the difference between the reference pressure and the measured pressure of each keyboard is aligned and displayed.
The method of claim 2,
The control unit,
A digital piano keying test system, characterized in that controlling the keys to be automatically keyed one by one in the order in which the keys are arranged, or controlling at least one key to be keyed simultaneously.
The method of claim 1,
The automatic keying unit,
A first finger bar for automatically keying a white key among the plurality of keys;
A second finger bar for automatically keying a black key among the plurality of keys; And
And a pressure sensor for measuring the keystroke pressure of the white key and the black key.

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