Socket Mobile iPAQ ユーザーズマニュアル

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PPENDIX 

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All bar code symbols/labels should satisfy the appropriate AIM 
Uniform Symbology Specification. 
 
Background Substrate: 
The bar code symbol should be printed on material (media) that 
is reflective and has a matte (not glossy) finish.  A background 
diffuse reflectance of at least 70% to 80% is desirable for 
optimum contrast.  Retro-reflective media should be used to 
obtain decode distances greater than 36 inches. 
 
Ink Color and Type: 
The inked bars should not exceed 25% reflectance at the 
wavelength that is being used for reading, whether printed with 
black ink or colored ink.  The reflectance value should not vary 
more than 5% within the same character. 
 
Voids and Specks: 
The code should be printed clearly, free of voids, specks, 
blemishes and lines that could “fool” the scanner.  Specks or 
blemishes in the white spaces, or false or missing bar sections 
could be interpreted by the reading equipment as part of the 
code.  Generally, the width of such flaws is more serious than the 
height.  Code symbols/ labels should be rejected if these defects 
are present. 
 
Definition: 
The bars in the bar code symbol should be well defined.  Their 
edges should not be rough or fuzzy, so that the bars and spaces 
have the proper widths intended for the bar code symbology 
used. 
 
Contrast: 
Background reflectance (that of the substrate on which the codes 
are printed) should always provide a good contrast relative to 
the ink reflectance (that of the code bars).  The difference 
between the two should be at least 37.5% at the wavelength 
used for reading. 
 

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