Measurements of lift plates

Abstract

An example apparatus includes a lift plate of a tray to hold a print medium. A support member is operatively connected to the lift plate. A sensor is attached to the support member to measure a distance of the lift plate from the sensor. A processor may receive a measurement of the distance of the lift plate from the sensor, and output an indicator describing an amount of print media in the tray based on the measurement of the distance of the lift plate from the sensor.

What is claimed is: 
     
         1 . An apparatus comprising:
 a lift plate of a tray to hold a print medium;   a support member operatively connected to the lift plate;   a sensor attached to the support member to measure a distance of the lift plate from the sensor; and   a processor to:
 receive a measurement of the distance of the lift plate from the sensor; and 
 output an indicator describing an amount of print media in the tray based on the measurement of the distance of the lift plate from the sensor. 
   
     
     
         2 . The apparatus of  claim 1 , wherein the processor is to send the indicator to a communication device remotely-located from the tray. 
     
     
         3 . The apparatus of  claim 1 , wherein the sensor is to detect a time-of-flight laser that is directed substantially perpendicular to the lift plate. 
     
     
         4 . The apparatus of  claim 1 , wherein the sensor is to calculate a height of the lift plate relative to a bottom of the tray based on the measured distance of the lift plate from the sensor. 
     
     
         5 . The apparatus of  claim 1 , wherein the distance between the sensor and the lift plate decreases as an amount of print media in the tray decreases. 
     
     
         6 . The apparatus of  claim 1 , wherein the indicator correlates the amount of print media in the tray as a function of an angle of rotation of the lift plate. 
     
     
         7 . A document management device comprising:
 a tray;   a lift plate in the tray to hold a print medium;   a sensor to measure a distance between the sensor and the lift plate; and   a processor to:
 receive a measurement of the distance between the sensor and the lift plate; and 
 generate an object identifier value corresponding to the measurement of the distance between the sensor and the lift plate. 
   
     
     
         8 . The document management device of  claim 7 , wherein the processor is to generate a qualitative description of an amount of print media in the tray based on the object identifier value. 
     
     
         9 . The document management device of  claim 8 , wherein the processor is to send any of the object identifier value and the qualitative description to a communication device remotely-located from the tray. 
     
     
         10 . The document management device of  claim 7 , wherein the object identifier value corresponds to an amount of print media in the tray as a function of an angle of rotation of the lift plate. 
     
     
         11 . The document management device of  claim 7 , wherein the sensor comprises an infrared sensor. 
     
     
         12 . A machine-readable storage medium comprising instructions that when executed cause a processor of an electronic device to:
 detect a print medium on a lift plate positioned in the tray;   automatically measure an angle of rotation of the lift plate as an amount of print media decreases on the lift plate;   generate an indicator that correlates the amount of print media in the tray as a function of the measurement of the angle of rotation of the lift plate; and   transmit the indicator to a communication device that is remotely-located from the tray.   
     
     
         13 . The machine-readable storage medium of  claim 12 , wherein the indicator comprises an object identifier value corresponding to the measurement of the angle of rotation of the lift plate. 
     
     
         14 . The machine-readable storage medium of  claim 12 , wherein the indicator comprises a qualitative description of the amount of print media in the tray based on the measurement of the angle of rotation of the lift plate. 
     
     
         15 . The machine-readable storage medium of  claim 12 , wherein the indicator comprises a color-coded indicator.