Difference between revisions of "AN0101 - Understanding LCD Panel Dimensions for Bezel Design"

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In all new SIM's technical documentation you'll find a Mechanical Design Package, or "MDP".  The Mechanical Design Package includes 3D STEP files that your mechanical designer can use to wrap an enclosure around a SIM.
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In all new SIM's technical documentation you'll find a Mechanical Design Package, or "MDP".  The Mechanical Design Package includes 3D STEP files that your mechanical designer can use to wrap an enclosure around a SIM.  
  
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There is also a simple 2D "blueprint style" drawing of each SIM in its MDP. For example, the SIM231 MDP has a 2D drawing which includes this diagram:
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There is also a simple 2D "blueprint style" drawing of each SIM in its MDP. In each drawing, depending on the touch technology for the specific SIM (e.g. Resistive, Capacitive, None) there are important dimensions of the various "zones" of the display you need to understand in order to create a bezel and mount the display in your enclosure.
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== Resistive Touch ==
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When using a SIM with Resistive Touch (LCD Option Codes starting with "R"), you'll find 2D drawings such as found in the SIM231-A01 Mechanical Design Package (MDP):
  
 
[[Image:SIM231_LCD2D.gif|center|700px| ]]
 
[[Image:SIM231_LCD2D.gif|center|700px| ]]
  
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Here's a definition of the terms in this diagram:
 
  
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=== Frame Outer ===
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The terms in this diagram are as follows:
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=== Frame Outer (FO) ===
 
Frame Outer is the outer frame of the LCD display.  Make sure if your bezel hangs down you give at least 2mm clearance outside this dimension.
 
Frame Outer is the outer frame of the LCD display.  Make sure if your bezel hangs down you give at least 2mm clearance outside this dimension.
  
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=== Touch Panel Outer ===
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=== Touch Panel Outer (TPO) ===
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The Touch Panel Outer dimension is the outer edge of a resistive touch panel's Mylar layers.  Any pressure applied with a gasket should ''not'' overhang this edge or the outer edge of the plastic will deform and affecting the performance of the touch layers. Typically a gasket will start just inside this dimension.
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The Touch Panel Outer dimension is the outer edge of a resistive touch panel's Mylar layers.  Any pressure applied with a gasket should ''not'' overhang this edge or the outer edge of the plastic will deform and affecting the performance of the touch layers. Typically the outer edge of any gasket will start just inside this dimension.
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=== Bezel Inner === 
 
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The Bezel Inner dimension is the inner edge of any gasket as well as the inner edge of any bezel opening.
 
  
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=== Touch Panel Visual Area ===
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=== Bezel Largest Opening (BLO) ===
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The Bezel Largest Opening is the largest dimension of the inner edge of bezel.  If you make the bezel any "more open" than this, end users will the see the metal silver-colored conductive traces that are along the edge of the touch panel.  The inner edge of your gasket can come to this dimension.
  
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Touch Panel Visual Area is the area on the touch panel where inside this dimension there is no silver-looking conductive traces visible.  These traces encircle a resistive touch panel and you don't want users to see this silver layer, so any bezel must come inside this dimension.
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=== Bezel Largest Opening (BSO) === 
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The Bezel Smallest Opening is the smallest dimension of the inner edge of bezel.  Do not make the bezel opening any smaller than this dimension or you may (with tolerance) make it difficult to select icons on the edge of your LCD.  The inner edge of your gasket can come to this dimension, but of course no further or your gasket will show outside your bezel.
  
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=== Touch Panel Active Area ===
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=== Touch Panel Sense Area (TPSA) ===
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Touch Panel Sense Area is the area where the touch panel can be pressed.  This usually extends a bit outside the LCD pixel area as the touch panels are made to support a wide variety of similar-sized LCD displays. It is important that your bezel gasket (if present) does not anywhere inside the sense area or software readings of the touch panel will be distorted.  It is critical that your bezel gasket (if present) does not straddle the edges of the sense srea or permanent damage may occur to the touch panel: ensure the inside edge of your gasket is no smaller than the Bezel Smallest Opening (BSO). 
  
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Touch Panel Active Area is the area where the touch panel can be pressed. This usually extends a bit outside the LCD pixel area.  If you have icons (etc) in the edges of the screen displayed, you want to make sure the full Touch Panel Active Area is accessible if possible. It helps the user press on those edges of the screen without having to dig their finger into the corner of your bezel.
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=== LCD Pixel Area (LCDPA) ===
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The LCD pixel area is the actual area occupied by pixels. You'll want to center the pixel area in your bezel and work backwards from the center of the pixel area to where you mount the SIM.   If you take the LCDPA width or height and divide by the number of pixels (800 and 480 respectively) you’ll get the pixel pitch which should match exactly the specs in the technical reference manual (TRM) posted on the web.
  
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=== LCD Active Area ===
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== Non-Touch ==
  
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The LCD active area is the actual area of the pixels. You want to center the Active Area in your bezel and work backwards from the center of the active area to where you mount the SIM.  If you take the AA width or height and divide by the number of pixels (800 and 480 respectively) you’ll get the pixel pitch which should match exactly the specs in the technical reference manual (TRM) posted on the web.
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== Capacitive Touch ==

Revision as of 07:55, 23 April 2014

In all new SIM's technical documentation you'll find a Mechanical Design Package, or "MDP". The Mechanical Design Package includes 3D STEP files that your mechanical designer can use to wrap an enclosure around a SIM.

There is also a simple 2D "blueprint style" drawing of each SIM in its MDP. In each drawing, depending on the touch technology for the specific SIM (e.g. Resistive, Capacitive, None) there are important dimensions of the various "zones" of the display you need to understand in order to create a bezel and mount the display in your enclosure.

Resistive Touch

When using a SIM with Resistive Touch (LCD Option Codes starting with "R"), you'll find 2D drawings such as found in the SIM231-A01 Mechanical Design Package (MDP):

SIM231 LCD2D.gif


The terms in this diagram are as follows:

Frame Outer (FO)

Frame Outer is the outer frame of the LCD display. Make sure if your bezel hangs down you give at least 2mm clearance outside this dimension.

Touch Panel Outer (TPO)

The Touch Panel Outer dimension is the outer edge of a resistive touch panel's Mylar layers. Any pressure applied with a gasket should not overhang this edge or the outer edge of the plastic will deform and affecting the performance of the touch layers. Typically the outer edge of any gasket will start just inside this dimension.

Bezel Largest Opening (BLO)

The Bezel Largest Opening is the largest dimension of the inner edge of bezel. If you make the bezel any "more open" than this, end users will the see the metal silver-colored conductive traces that are along the edge of the touch panel. The inner edge of your gasket can come to this dimension.

Bezel Largest Opening (BSO)

The Bezel Smallest Opening is the smallest dimension of the inner edge of bezel. Do not make the bezel opening any smaller than this dimension or you may (with tolerance) make it difficult to select icons on the edge of your LCD. The inner edge of your gasket can come to this dimension, but of course no further or your gasket will show outside your bezel.

Touch Panel Sense Area (TPSA)

Touch Panel Sense Area is the area where the touch panel can be pressed. This usually extends a bit outside the LCD pixel area as the touch panels are made to support a wide variety of similar-sized LCD displays. It is important that your bezel gasket (if present) does not anywhere inside the sense area or software readings of the touch panel will be distorted. It is critical that your bezel gasket (if present) does not straddle the edges of the sense srea or permanent damage may occur to the touch panel: ensure the inside edge of your gasket is no smaller than the Bezel Smallest Opening (BSO).

LCD Pixel Area (LCDPA)

The LCD pixel area is the actual area occupied by pixels. You'll want to center the pixel area in your bezel and work backwards from the center of the pixel area to where you mount the SIM. If you take the LCDPA width or height and divide by the number of pixels (800 and 480 respectively) you’ll get the pixel pitch which should match exactly the specs in the technical reference manual (TRM) posted on the web.

Non-Touch

Capacitive Touch

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