Specifications

215
Variation of ambient light
This imager will detect the ambient brightness from the obtained image and calculate the optimum
exposure time or sensitivity (gain) to prepare for the next image capture. Therefore, if a new
capture is made in an environment different from the previous capture, it may be required to
repeat the capture several times until the optimum value can be calculated. In addition, the imager
is affected by various light-related conditions, such as a location by a window, overcast weather,
sun and shade, morning and evening settings, etc., which generally are not a conscious
consideration for humans (and are handled without conscious thought).
Reflected light from the illumination LED, backlight
In addition to direct light from the light source (producing the effect of backlight), reflected light
of the illumination LED, re-reflected light on the lens in an excessively bright environment, etc.,
may cause part of the symbol to disappear into the white background or hamper the correct
exposure calculation, resulting in decoding no longer being possible. Such a detrimental effect of
the illumination LED can be avoided by the “LED Light Intensity Adjustment Function”,
described later.
Position of the Imager
The Imager is oriented at a 45-degree downward angle, if the terminal is held horizontally. Thus,
the Imager faces obliquely upward if the terminal is held vertically as shown below, and faces
obliquely downward if the terminal is held horizontally. And, if the terminal is inclined 45 degrees,
the Imager will now be held horizontally, so it will face straight towards the object.
In order to avoid a mirror reflection (occurs within ±5 degrees from the shooting direction of the
Imager), it is recommended to hold the Imager at a 30 degree inward inclination so that image
capturing can be performed under a condition where the target symbol is slightly above the top
edge of the terminal.
Fig. 5.2