Test equipment for color printing

• US 6,332,047 B1
• Filed: 08/07/1998
• Issued: 12/18/2001
• Est. Priority Date: 12/06/1995
• Status: Expired due to Fees

• Current Assignee: Laurie Mullaney Associates Limited
• Original Assignee: Laurie Mullaney Associates Limited
• Inventors: Mullaney, Lawrence, Sebborn, Martin
• Primary Examiner(s): Boudreau, Leo
• Assistant Examiner(s): PATEL, KANJIBHAI B
• Application Number:
  US09/077,730
• Time in Patent Office: 1,229 Days
• Field of Search: 382/298, 430/18, 430/49, 430/303, 430/300, 101/463.1, 101/465
• US Class Current: 382/298
• CPC Class Codes: G01B 11/285 using photoelectric detection means

Abstract

The invention provides a method and apparatus for measuring an imaged printing plate which enables the user to assess the ratio of imaged to non-imaged surface area. According to the method light is projected from a light source (3) over that area of the imaged plate to be measured, the area is enlarged by magnifying means (2), an image of the enlarged area is obtained via a c.c.d. camera (1), electronic signals are captured and red from the camera via an electronic framegrabber (7) to provide an electronic image representing the enlarged area, and the captured image is fed to an electronic circuit for analysis to determine said ratio of surface area.

Claims

1. A method of measuring an imaged printing plate for the ratio of imaged to non-imaged surface area, comprising providing even light over that area of the imaged plate to be measured, enlarging said area via magnifying means, obtaining an image of the enlarged area via a c.c.d. camera, capturing electronic signal fed from the camera via an electronic frame grabber to provide an electronic image representing the enlarged area, feeding the captured image to an electronic circuit, analyzing the captured image by the electronic circuit to determine the ratio of imaged to non-imaged surface area and providing an output of the ratio of imaged to non-imaged surface area.

2. A hand-held apparatus for measuring an imaged printing plate for the ratio of imaged to non-imaged surface area comprising a source for providing even light over the area of the plate to be measured, means for magnifying said area, a c.c.d. camera for producing an enlarged image of said area, a frame grabber for capturing the enlarged image in electronic form, and an electronic circuit for analyzing and determining the ratio of imaged to non-imaged surface area.

3. Apparatus according to claim 2, wherein the c.c.d. camera has magnification means in the form of a high magnification lens.

4. Apparatus according to claim 2, wherein a light source is provided which can be set to a desired light value by a light control unit via an electronic circuit.

5. Apparatus according to claim 4, wherein said electronic circuit includes said framegrabber.

6. Apparatus according to claim 2, wherein the framegrabber has an associated memory for the capture and temporary storage of images from the c.c.d. camera, and wherein the framegrabber is connected to an electronic circuit for the computation of the images.

7. Apparatus according to claim 2, wherein a casing is provided for the c.c.d. camera and associated components, and in which the camera is mounted in such a way that it can be located with the aid of an aiming sight over that area of the imaged plate to be measured.