JPH04128409U - recording level control device - Google Patents

Abstract

(57) [Summary] [Purpose] To enable automatic recording level setting and prevent rapid distortion when the input signal exceeds full scale (0 dB). In addition, control is performed using digital signals,
The recording level is displayed numerically, allowing the user to recognize the accurate value, and improving operability. Furthermore, by combining automatic recording level adjustment and manual recording level adjustment, it is possible to make fine adjustments according to the user's preferences. [Configuration] An analog signal control unit that controls the level of the input analog signal according to instructions from the microcomputer, a digital volume that increases/decreases the value of the input digital signal and outputs it, and a unit that converts the value of the digital signal numerically. A level meter for display is provided, the input signal is set under microcomputer control so that the input signal does not exceed 0 dB, and the value of the set input signal is displayed numerically on the level meter.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is a recording recorder for PCM recording equipment using an analog/digital converter. Relating to a bell control device.

0002

[Conventional technology]

Conventional analog/digital converter input level setting methods include Japanese Patent Application Laid-Open No. 62-2 As disclosed in Japanese Patent No. 57219, from the control circuit using an electronic volume There is a method of controlling the gain using digital signal commands.

0003 Furthermore, the recording level control device of conventional PCM recording equipment has the configuration shown in Figure 1. The recording level is adjusted by the following operations.

0004 First, the analog signal input from the input terminal is connected to a mechanical recording volume. After passing through a low-pass filter (hereinafter referred to as L.P.F.), the sample sampled/held at the pulling frequency. The sampled/held signal is , is converted into a digital value by an A/D converter, and is converted into a digital value according to the input signal level. A total signal is obtained. Furthermore, the level is controlled by a microcomputer through I/O and DSP. displayed on the meter.

[0005] When the input signal is around full scale (0 dB) and exceeds 0 dB, distortion occurs. Since it increases rapidly, it changes gradually to below 0dB depending on the recording volume. It was necessary to change it to a level where it would not be a problem.

[0006] Also, since adjustments are made using a mechanical volume, how many dB is the attenuation? The disadvantage is that it is difficult to adjust the level because it is not possible to display the Ta.

[0007]

[Problem that the idea aims to solve]

This invention was made in view of the above circumstances, and it improves the recording level of PCM recording equipment. When setting the input signal, make sure that the input signal does not exceed full scale (0 dB). Automatically controls and configures the signal as well as displays the configured attenuation level. The technical challenge is to do so.

[0008]

[Means to solve the problem]

In order to solve the above problems, this invention inputs analog signals and converts them into digital signals. A recording device that processes signals using a microcomputer and a program memory. The level of the input analog signal is controlled by the controller section and the instructions from the microcontroller section above. The input digital signal is controlled by the analog signal control section and the instructions from the microcomputer section mentioned above. digital volume, which increases or decreases the value of a digital signal, and It has a level meter that numerically displays the signal value, and is controlled by the microcomputer section mentioned above. Set the input signal so that the input signal does not exceed 0 dB, and The level meter is characterized in that the value of the input signal determined by the input signal is displayed numerically on the level meter.

[0009]

[Effect]

According to this invention, the input signal can be accurately adjusted to full scale (0 dB) using microcomputer control. ) Input signal settings can be automatically configured to avoid exceeding

0010 Furthermore, it becomes possible to display the value of the recording level numerically.

[0011]

【Example】

An example of the digital automatic recording level control device of the present invention will be described below using FIGS. 1 to 5. I will explain.

0012 FIG. 2 is a block diagram of a digital automatic recording level control device according to the present invention.

[0013] In the figure, (1) is a mechanical volume, which converts the input analog signal into a manual volume. It is attenuated by Al operation. (2) L.P.F, which is a high frequency component of the input signal. (3) is an analog level control circuit, which is a ladder resistance type electronic voltage control circuit. It uses a volume to control the level of an analog signal with a digital signal. Ru.

[0014] (4) is an amplifier, which is used as a buffer for analog signals. (5) is San This is a pull-hold circuit that holds the input signal depending on the sampling frequency. (6) is an A/D converter, which converts an analog signal into a digital value.

[0015] (7) is a digital volume, which converts digital signals into UP/DOWN signals. Increase/decrease the digital value. (8) is a digital I/O buffer. ( 9) is a digital signal processor (D.S.P), which processes various digital signals. do the same thing. (10) is the microcomputer section, which controls the main unit by executing the control program. control the location. (11) is a level meter, which displays the attenuation level.

[0016] Then, the microcomputer unit (10) performs the following steps according to the flowcharts shown in Figures 3 and 4. , controls the analog level control circuit (3) and digital volume (7) This allows you to automatically adjust and set the recording level.

[0017] The control program will be explained below.

[0018] Figure 3 shows a program for automatically setting the recording level (hereinafter referred to as ATT level). 2 is a flowchart of the program.

[0019] First, the program counter of the microcomputer section (10) is set to the automatic recording (AUTO) program. When this program is started, the S1 step is set to the first address of the program routine. Press to enter recording stop mode, and use step S2 to set the recording level for a certain period of time (about a few seconds). monitoring. Step S1 switches to recording stop mode, and step S2 stops recording for a certain period of time (about a few seconds). Monitor recording levels.

[0020] In step S3, hold the peak of the maximum value of the signal input during this monitoring period. and stored in the memory of the microcomputer section (10) as a digital value.

[0021] Next, in the S4 step, the peak held value in the S3 step exceeds -6 dB. It is determined whether it exceeds or exceeds -12 dB.

[0022] If it is determined that it is -12dB or more, control is transferred to step S8, and -6dB If it is determined that the time exceeds 90, in step S5, the time exceeds 90. Determine whether the time exceeds msec.

[0023] If it is determined that it exceeds 90 msec, in step S6, the analog level A signal is output to the control circuit (3) to attenuate the analog input level, and step S7 Then, the signal level obtained as a result of the processing in steps S4 to S6 is displayed as the ATT level. After that, control is returned to step S2.

[0024] If it is determined that the time is 90 msec or less, control is transferred to step S8.

[0025] Here, the comparison value was determined to be 90 msec, but other values may be used.

[0026] In step S8, the ATT level of the analog level control circuit (3) is set to 0 dB. do.

[0027] In step S9, cancel the recording stop mode and start recording in step S10. let

[0028] Figure 4 shows how this device can be used to manually adjust the ATT level according to the user's preference. It is a flowchart of a program to be executed.

[0029] Steps S11 to S17 are the same as steps S1 to S7 in FIG. Similarly, the program counter of the microcomputer section (10) is set to the automatic recording (MANUAL) program. This is set to the first address of the program routine, and when this program is started, S1 Step 1 enters recording stop mode, step S12 stops recording for a certain period of time (about a few seconds) Monitor recording levels.

[0030] In step S13, peak hold of the maximum value of the signal input during this monitoring is performed. is performed and stored in the memory of the microcomputer section (10) as a digital value.

[0031] Next, in step S14, the value held at the peak in step S13 is -6. It is determined whether it exceeds dB or -12 dB or more.

[0032] If it is determined that it is -12dB or more, control is transferred to step S18, and -6 If it is determined that the dB has been exceeded, in step S15, the time for which the dB has been exceeded is determined. It is determined whether the time exceeds 90 msec.

[0033] If it is determined that the time exceeds 90 msec, the analog level is Outputs a signal to attenuate the analog input level to the S17 step control circuit (3). The signal level obtained as a result of the processing in steps S14 to S16 is set to the ATT level. After that, the control returns to step S12 again.

[0034] If it is determined that the time is 90 msec or less, control is transferred to step S18.

[0035] Here, the comparison value was determined to be 90 msec, but other values may be used.

[0036] In step S18, the ATT level value is displayed, and in step S19, the user's Instruct the increase/decrease of the ATT level by operation, and follow this instruction to adjust the analog level in step S20. Outputs an ATT level increase/decrease command to the gray level control circuit. After that, step S21 Steps S18 to S21 are performed until the user inputs an instruction to start recording. Do it repeatedly.

[0037] When the recording start instruction is input, the recording stop mode is canceled in step S22. Then, start recording in step S23.

[0038] Figure 5 shows that the ATT level can be adjusted entirely manually by the user using this device. 2 is a flowchart of a control program for performing the operation.

[0039] The program counter of the microcomputer section (10) is a manual level setting program. It is set to the start address of the routine and when this program is started, the S23 step is executed. to enter the recording stop mode, and then set the recording level for a certain period of time (about a few seconds) in step S24. monitor the system.

[0040] In step S25, peak hold of the maximum value of the signal input during this monitoring is performed. This value is displayed as the ATT level value in step S26.

[0041] In step S27, the user performs an instruction to increase or decrease the ATT level, and this instruction is According to the instructions, in step S28, issue a command to increase or decrease the ATT level to the analog level control circuit. Strengthen. Thereafter, until the user inputs an instruction to start recording in step S29, S Steps 24 to S28 are repeated.

[0042] When the recording start instruction is input, the recording stop mode is canceled in step S30. Then, start recording in step S31.

[0043]

[Effect of the idea]

As mentioned above, by using the automatic recording level adjustment of this invention, the automatic recording level can be adjusted. Since it is possible to set the It is possible to record without excessive distortion.

[0044] Also, since it is controlled using digital signals, the recording level can be adjusted numerically. This enables display and allows the user to recognize accurate values, improving operability.

[0045] Furthermore, automatic recording level adjustment and manual recording level adjustment are combined. This makes it possible to make fine adjustments according to the user's preferences.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a recording level control device for a conventional PCM recording device.

FIG. 2 is a block diagram of a digital automatic recording level control device according to the present invention.

FIG. 3 is a flowchart of a program for automatically setting recording levels.

FIG. 4 is a flowchart of a program for manually fine-tuning the recording level after it is automatically set.

FIG. 5 is a flowchart of a program for performing manual operations.

[Explanation of symbols]

1. volume 2. low pass filter 3. Analog level adjustment circuit 4. amplifier 5. sample hold circuit 6. D/A converter 7. digital volume 8. Digital I/O buffer 9. digital signal processor 10. Microcomputer section 11. level meter

Claims (1)

[Scope of utility model registration request] [Claim 1] A recording device that inputs an analog signal, converts it to digital, and processes the signal, comprising a microcomputer section having a microcomputer and a program memory, and controlling the level of the input analog signal according to instructions from the microcomputer section. According to instructions from the analog signal control section and the microcomputer section above,
It has a digital volume that increases or decreases the value of the input digital signal and outputs it, and a level meter that displays the value of the digital signal numerically, and is controlled by the microcomputer section so that the input signal does not exceed 0 dB. A recording level control device characterized in that the input signal is set as follows, and the value of the set input signal is numerically displayed on the level meter.