PLATE PALLET STOCK DETECTION

Abstract

A plate stock detection apparatus for detecting plates remaining on a plate pallet (13) on an automatic plate pallet loading system (18) configured to load plates into an imaging device, which includes a plate pallet adaptor (11). The plate pallet is placed on top of the adaptor; and plate pallet stock detectors (15, 16, 21, 31) measure plates left on the plate pallet. A plate pallet elevation system (12) elevates the plate pallet in response to feedback plate pallet stock detectors.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

Reference is made to commonly-assigned copending U.S. patent application Ser. No. ______ (Attorney Docket No. 94853/NAB), filed herewith, entitled PLATE PALLET ALIGNMENT SYSTEM, by Korolik et al., the disclosure of which is incorporated herein.

FIELD OF THE INVENTION

The present invention relates to an apparatus and methods for detecting the amount of plate stock left in a pallet of printing plates configured to be loaded into a computer-to-plate (CTP) imaging device.

BACKGROUND OF THE INVENTION

The CTP systems known today provide manual user input into a system controller of information relating to plate amount and plate type, which are loaded into the various plate trays associated with the CTP device. This data is updated further on by the system controller by counting down the number of plates used during the plate imaging process.

The present invention provides an automatic technique, which does not require manual entry of plate quantitative data. The present invention detects plates availability and alerts the user when plate replenishment is required.

SUMMARY OF THE INVENTION

Briefly, according to one aspect of the present invention a plate stock detection apparatus detects plates remaining on a plate pallet on an automatic plate pallet loading system which is configured to load plates into an imaging device. Plate pallet stock detectors measure stock of plates left in the plate pallet and a plate pallet elevation system elevates the plate pallet in response to feedback from the plate pallet stock detectors.

These and other objects, features, and advantages of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings wherein there is shown and described an illustrative embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustrating a plate pallet stock detection system using a light source and detector placed on opposite sides of the pallet;

FIG. 2 is a schematic illustrating a plate pallet stock detection system using a light source and detector placed in same side of the pallet and a reflective surface on the opposite side; and

FIG. 3 is a schematic illustrating a plate pallet stock detection system using a physical detector.

DETAILED DESCRIPTION OF THE INVENTION

The present invention describes apparatus and methods for detection of printing plate quantities left in a plate pallet for an automatic pallet loading (APL) device attached to a computer-to-plate (CTP) device.

Referring to FIG. 1, plate pallet 13, attached to plate pallet adaptor 11, is placed on a plate pallet elevation system 12. The plate pallet elevation system 12 is used to elevate the plate pallet 13, towards a plate loading system 18. Encoder 14 detects the elevation level of the plate pallet elevation system 12.

Light source 15 is directed towards light detector 16 via the optical path 17, in order to detect the existence of a plate ready to be loaded by plate loading system 18. Another embodiment, shown in FIG. 2, comprises light source 15 and light detector 16, located on one side of the pallet, with the light reflected back via a reflected optical path 22 from a reflective surface 21 located at the opposite side of the pallet.

When light is detected by light detector 16, the plate pallet elevation system 12 raises plate pallet 13. This process is iterative and is performed until the light detector 16 is not able to detect the light generated by light source 15.

Light source 15 and light detector 16 might be replaced by a physical detector 31, shown in FIG. 3, such as a micro switch, inductive device, or optical device. This will indicate that plate pallet 13 is in the right level where the plate loading system 18 can pick a plate from pallet 13 in order to load it into the imaging device. This method also enables a processor to calculate the number of blank plates left in pallet 13 for further usage. The calculation will be done by knowing the original amount of plates or pallet height in the plate pallets, the elevated height of the plate pallet elevation system 12 derived from encoder 14, and the original elevator position. A simple calculation will determine the number of blank plates left, and this information will be alerted to the user to the need for a new pallet.

The light detector 16, also helps to avoid a hazardous situation aliasing from elevating plate pallet 13 to an uncontrolled height, possibly damaging the APL and CTP devices.

The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the scope of the invention.

Parts List

• 11 plate pallet adaptor
• 12 plate pallet elevation system
• 13 plate pallet
• 14 encoder
• 15 light source
• 16 light detector
• 17 optical path
• 18 plate loading system
• 21 reflective surface
• 22 reflected optical path
• 31 physical detector

Claims

1. A plate stock detection apparatus for detecting plates remaining on a plate pallet on an automatic plate pallet loading system configured to load plates into an imaging device comprising:

a plate pallet adaptor wherein said plate pallet is placed on top of said adaptor;

plate pallet stock detectors configured to measure stock of plates left on said plate pallet; and

a plate pallet elevation system configured to elevate said plate pallet in response to feedback from said plate pallet stock detectors results.

2. The apparatus of claim 1 wherein said plate pallet stock detectors comprising a light source and an optical light detector positioned on two opposite sides of said plate pallet.

3. The apparatus of claim 1 wherein said plate pallet stock detectors comprising a light source and an optical light detector positioned on one side of said pallet and a reflective surface on an opposite side of said plate pallet, for reflecting light back to said light detector.

4. The apparatus of claim 3 wherein said reflective surface is a mirror.

5. The apparatus of claim 1 wherein said plate pallet stock detectors comprises a physical detector.

6. The apparatus of claim 5 wherein said physical detector is a mechanical or electronic sensor.

7. The apparatus of claim 1 wherein said plate pallet stock detectors are optical detectors.

8. The apparatus of claim 1 wherein said plate pallet stock detectors are inductive detectors.