JPH0760592B2 - Level display device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a level display device for selectively driving a plurality of display elements according to a signal level of an audio signal or the like to perform digital level display, In particular, it relates to one having a function of switching the display resolution.

[Conventional technology]

Generally, in tape recorders and the like, an analog signal level meter using a VU meter or a level meter in which a plurality of display elements such as light emitting diodes are arranged to digitally display the input signal level as a bar graph is used. The signal level of is displayed.

Conventionally, as a level display device for performing digital level display, for example, as shown in Japanese Utility Model Publication No. Sho 55-19322, an analog input signal is converted into a digital signal,
It is known that a plurality of display elements are selectively driven via a decoder by this digital signal.
This conventional example further has a function of decoding a digital signal corresponding to a level within a predetermined range centered on a predetermined level by an auxiliary decoder to display a high resolution level.

[Problems to be solved by the invention]

In a level display device that performs digital level display by selectively driving a plurality of display elements according to the input signal level, the display range and display resolution are determined by the number of display elements, and the display range is wide. However, there is a problem in that the number of display elements becomes enormous when an attempt is made to perform high-resolution display with a group of display elements. In addition, even when a separate display element for high resolution display is provided, the increase in the number of display elements cannot be avoided,
There is a problem that the device becomes large in size, and it is inconvenient to read the displayed signal level.

Therefore, the present invention, without increasing the number of display elements,
The present invention provides a level display device having a novel structure that enables high-resolution display, downsizing of the device, and easy reading of a signal level.

[Means for solving problems]

In order to solve the above-mentioned problems, a level display device according to the present invention selectively drives a plurality of display elements arranged in parallel and a plurality of display elements according to an input signal level. A display control unit for performing display control, a memory for storing display control data for performing display control of the level display unit by the display control unit with a predetermined resolution, and a display in a display control state with the predetermined resolution. For each display range obtained by dividing the range into a plurality of areas, a plurality of memories storing display control data for performing display control of the level display section with high resolution, and display control data read from the memories are displayed. The data selector is selectively supplied to the control unit.

[Work]

In the level display device according to the present invention, by selecting the display control data stored in each memory with the data selector, the resolution of the display control of the level display unit is switched, and the scale around the predetermined signal level is set. The enlarged level is displayed.

〔Example〕

An embodiment of the level display device according to the present invention will be described below in detail with reference to the drawings.

The block circuit diagram of FIG. 1 shows an embodiment in which the present invention is applied to a level display device for a digital audio system. In this embodiment, 16-bit audio input data D _{IN which} is a digitized audio signal is a signal. It is assumed that the display control unit 2 is supplied from the input terminal 1.

The level display device of this embodiment has a level display unit 3 having 31 light emitting diodes L ₁ , L ₂ , ..., L ₃ arranged in a line.
The display control of the level display unit 3 is performed by the display control unit 2 described above.
7 memory 11,12,13,14,15,16,17 for storing display control data D _S for performing different resolutions according to
And a data selector switch 5 for selectively connecting one of the memories 11, 12, 13, 14, 15, 16, 17 to the display control section 2.

In this embodiment, in the first memory 11, the signal level indicated by the audio input data D _IN is associated with 0 dB to −10 dB with a resolution of 1 dB in the unit of decibel [dB], and with a resolution of 2 dB. Display control data D ₁ as shown in FIG. 2A that corresponds to −10 dB to −40 dB and corresponds to −40 dB to −60 dB with a resolution of 4 dB is stored. Then, when the data selector switch 5 is set so as to select the first memory 11, the display control unit 2 stores the memory.
Display control data D ₁ supplied from 11 and the above signal input terminal
By comparing with the audio input data D _IN supplied from 11, the level of the signal level indicated by the above audio input data D _IN is determined in the range of 0 dB to −60 dB, and the above level display is performed. The 31 light emitting diodes L ₁ , L ₂ , ..., L ₃ of the section ₃ are selectively driven to emit light. here,
When the above audio input data D _IN is displayed in hexadecimal, for example [2
62A], the display control unit 2 compares the display control data D ₁ read from the first memory 11 with the input data D _IN ,
The signal level [262A] indicated by the input data D _IN is [241A] of the signal level indicated by the display control data D ₁ .
3] It is judged to be -10 dB corresponding to the range of not less than [2AEO], and the light emitting diodes L ₁₁ , L ₁₂ , ..., L ₃₁ of the level display section 3 are caused to emit light as shown in FIG. 3A.

In addition, in this embodiment, the second memory 12 is
The display control data D ₂ as shown in FIG. 2B, which is associated with the ₃₁ light emitting diodes L ₁ , L ₂ , ..., L ₃₁ in the range of −9.0 dB to −1.2 dB with a resolution of 0.1 dB, is stored. There is. The display control data D ₂ is obtained by enlarging the display scale in the range of −9 dB to −12 dB centered at −10 dB by the display control based on the display control data D ₁ stored in the first memory 11. 0.1
The resolution is shown in dB.

That is, the data selector switch 5 causes the second
When the memory 12 of the second memory 12 is selected, the signal level [262A] indicated by the input data D _IN is
The display control unit 2 determines that the signal level indicated by the display control data D ₂ read from [25FE] or more and less than [266F] is −10.5 dB, and as shown in FIG. It is displayed by the light emission of ₁₆ , L ₁₇ , ..., L ₃₁ .

Furthermore, in this embodiment, in addition to the above -10 dB vicinity, -12
Each display as shown in FIGS. 2C to 2G for expanding the scale around each signal level of dB, −14 dB, −16 dB, −18 dB and −20 dB and displaying it with a resolution of 0.1 dB. control data _{D 3, D 4, D 5} , D 6, the D ₇ is stored in the third to seventh memory 13,14,15,16,17, each memory 12 and 13 in the data selector 5 , 14, 15, 16, 17 are selected so that the vicinity of six signal levels can be selectively enlarged and displayed.

As in this embodiment, the display control data D ₂ for enlarging the display scale around the specific signal level in the level display based on the display control data D ₁ stored in the first memory 11, for example −10 dB, is displayed. If the display control is performed by reading from the memory 12 of _{No. 2} , the vicinity of −10 dB can be obtained without increasing the number of display elements of the level display unit 3, that is, the light emitting diodes L ₁ , L ₂ , ..., L _31. It can be displayed with a resolution of 0.1 dB. In addition, as described above, if the scale is enlarged centering on a specific signal level and high resolution display is performed, the display content is easy to read. Further, in this embodiment, by selecting the second to seventh memories 12, 13, 14, 15, 16 and 17 by the data selector switch 5, six kinds of signal levels, that is, −10 dB, −12 dB, − 14d
B, -16dB, -18dB, it is possible to selectively expand the scale against -20 dB, 31 light emitting diodes of the level display unit _{3 L 1, L 2, ...} , the L _31, -9.0dB~- Level display can be performed with a resolution of 0.1 dB over a wide range of 21.5 dB.

In the above-described embodiment, the display control unit 2 compares the audio input data D _IN with the display control data D ₁ to determine the light emitting diodes L ₁ , L ₂ , ..., L ₃₁ of the level display unit 3. Although it is designed to drive light emission selectively, each light emitting diode
The lookup table data for performing selective light emission drive for L ₁ , L ₂ , ..., L ₃₁ is stored in the memory, and the lookup data is directly read from the memory using the input data D _IN as an address. Alternatively, each of the light emitting diodes L ₁ , L ₂ , ..., L ₃₁ may be selectively driven to emit light.

〔The invention's effect〕

As is apparent from the above description of the embodiments, in the level display device according to the present invention, a memory for storing display control data for performing display control of the level display unit by the display control unit with a predetermined resolution, and the above-mentioned predetermined For each display range obtained by dividing the display range in the display control state with the resolution of
Since a plurality of memories for storing display control data for performing display control of the level display section with high resolution are provided, by selecting the display control data stored in each memory with the data selector, With respect to the entire display range in the display control state with a predetermined resolution, level display can be performed with high resolution for each divided display range. Therefore, high-resolution level display can be performed without increasing the number of display elements in the level display unit.
It is easy to read the display contents, and the size can be reduced.

[Brief description of drawings]

FIG. 1 is a block circuit diagram showing one embodiment of the level display device according to the present invention, and FIGS. 2A to 2G are each display stored in the first to seventh memories in the above embodiment. It is each explanatory view which shows the contents of the control data typically,
FIG. 3A and FIG. 3B are schematic diagrams respectively showing display examples by the level display section in the above embodiment. 1 …… Signal input terminal 2 …… Display control section 3 …… Level display section 5 …… Data selector switch 11,12,13,14,15,16,17 …… Memory L ₁ , L ₂ ,…, L ₃₁ ...... Light emitting diode

Claims (1)

[Claims] 1. A level display section having a plurality of display elements arranged in parallel, a display control section for performing display control for selectively driving the plurality of display elements according to an input signal level, and the display control section. A memory for storing display control data for performing display control of the level display unit with a predetermined resolution by the above, and the level for each display range obtained by dividing the display range in the display control state with the predetermined resolution into a plurality of A plurality of memories for storing display control data for high-resolution display control of the display unit, and a data selector for selectively supplying the display control data read from the memories to the display control unit are provided. Level indicator.