Display device

A display in the art, a device for optical signaling of variable information ( states and values ​​), in particular measurements. They differ from plate, which present consistent information. The work system provide advertisements represents a interface between the human and a technical process or the environment

A display may have very different designs and are based on different technical implementation. A distinction is mechanical, electromechanical and electronic displays. Depending on the type and significance of the display itself can be subdivided them into binary displays, scales ads, Numerical and graphical displays. In ergonomics, the DIN EN 8942-2 distinguishes between optical, acoustic and tactile displays.

• 2.1 scale display
• 2.2 digit display

Designs and technical implementations of ads

Mechanical displays

In turn, mechanical displays continuous and discrete indicators are distinguished.

Examples of continuous mechanical displays:

• Mechanical tachometer set the speed of a shaft into a proportional thereto angle of a pointer.
• A float, including on oil tanks, shows a " clock " called device to the level.
• Water level indicator or short level, as they are found in many rivers, or water or level indicators, such as on boilers or coffee makers, show by direct view of the liquid level, often through a sight glass, the degree of filling and the water level of.
• Liquid thermometer
• Bimetallic thermometer
• Analog mechanical scales (pointer, moving or projected scale )
• Tuning scale for tuning to radio

Example of discrete mechanical displays:

• Railroad semaphore signals (operation via cable ): With the design with one arm two states can be displayed: "Ride " ( arm has obliquely upward ) and " Stop" ( arm is horizontally aligned ). Signals with two arms may additionally " Slow Ride" signal.
• , Indicator fuses to indicate a blown fuse element
• Mechanical pedometer and odometer; general: drum type register
• Water meters, gas meters
• Folding works on digital watches and clocks and flip-digit displays in stations and airports

Electromechanical ads

Continuous electromechanical displays:

• Scale Dials mechanical pointer Moving-coil
• Moving iron

• Mirror galvanometer

• Reed frequency meter
• Electrolytic hours of operation or power meter
• Electrometer

Discrete electromechanical displays:

• Electromechanical counter with digits roles with Ferrari engine in energy meters
• In odometers

Electrical and electronic displays

Electrically addressed displays, without moving parts can be Binary ads, keyed advertisements, as well as analog displays ( bar graph display, magic eye ) or themselves. The term digital display is usually a digital display meant.

Technical Realization ( examples):

• Signal lamps (bulbs light bulb or light emitting diodes )
• Light emitting diodes ( LEDs); binary, color change, digital display or bar graph
• Organic light emitting diodes ( OLEDs)
• Liquid crystal displays (LCDs); Sign, symbol, figure or image display (smartphones, monitors, flat screens)
• Fluorescent displays ( VFDs ); Character or symbol representation, also bar graph displays, Magic Eye
• Braun tubes; yx - representation in picture tubes, oscilloscopes, spectrum analyzers, measurement receivers, representation in polar coordinates to radar
• Bulbs ( indicator light ) (binary or brightness comparison or flashing at different frequencies )
• Nixie tubes ( digital display )

Usual types of control complex electrical or electromechanical displays are:

• Vector oriented control
• Raster or matrix display
• Segment display ( seven- segment display, Fourteen -segment display binary symbol display )

The screen (also monitor, display, Smart Display ) is a very universal indicator instrument. As a Braun tube it can be driven vector and raster -oriented.

Increasingly liquid crystal display panels for use, which are activated as a grid-like matrices.

Are also widespread LC - seven- segment displays, as they occur Bracelet and radio controlled watches including in digital instruments.

A virtual retinal display projects the information directly onto the retina of the eye.

Projection displays project alphanumeric characters or symbols on a wall or a screen. When alarm clocks with projection display a seven segment display is projected, while among others came in the early mainframes number advertisements are used, which for each point (point ) per 10 bulbs, 10 collimator lenses, gobos 0 .. 9 and 10 correspondingly aligned lenses had to represent each digit in the same position on a ground glass can. For projection of video images (video projector) on big screens consuming facilities such as the Eidophor system were previously necessary. Since the 1990s, there is this projection techniques with LCDs or DLPs, in some countries called beamer.

Head -up displays are reflected in a semi- transparent plate ( windshield, separate beam splitter wheel).

Show in metrology

In the basic for metrology DIN 1319-2 is at " measuring instruments with direct read-out " among others differed in scale display and digital display.

Scale display

When a measuring instrument with analog display continuously presents itself as output a mark ( eg a particular point in a physical pointer or a screen pointer, a light pointer ( see, eg, also mirror - galvanometer ), an edge of the meniscus of a liquid column ) usually for a job the scale one, or the scale is set to it. For physical pointers see, eg, under Analog multimeter, analog instrument.

Scale Dials can also be found in a variety of mechanical measuring instruments such as scales, calipers; latter using a vernier for accurate readability. Mirror scale additionally possess a mirror sector behind the pointer, in order to facilitate and thus avoid parallax error when reading vertical reading.

Analogue clocks, stopwatches and measuring screws have 2 to 3 hands to increase the reading accuracy.

The band display for displaying either a variable number of segments is lit ( discontinuous band display) or a continuously varying length of the tape is displayed. It may be a scale display or serve only for qualitative assessment. See bar graph display or Magic Eye.

Numeric display

In a gauge in which the output is quantized in a fixed given steps numerical representation of the measured quantity, batch number (sum ) of quantization or the number (sum ) of pulses in a sequence of numbers appears. The number advertisements are distinguished by the principles of digits to represent. See Section Electrical and electronic displays. Used earlier digits ads per point ten discrete, backlit numerals that were considered or projected directly on the basis of the lighting.

Numeric displays have the disadvantage that trends and the absolute magnitude are not recognizable at first glance. Therefore have digital multimeter ( DMM short, ie, those with a numeric display), sometimes also a quick bar graph or a pointer element, but also consist of discrete display elements ( see picture right).

Benefits are for example the right representability of reading over wide ranges by commas variable and that is also displayed units as well as self-luminous displays the high visibility in low light conditions.