Audio/video quality monitoring system

• US 4,623,837 A
• Filed: 06/14/1985
• Issued: 11/18/1986
• Est. Priority Date: 06/14/1985
• Status: Expired due to Term

• Current Assignee: Discovision Associates (Pioneer Corporation)
• Original Assignee: Discovision Associates (Pioneer Corporation)
• Inventors: Efron, Edward, Kim, Young B., McPherson, James O.
• Primary Examiner(s): Tokar, Michael J.
• Application Number:
  US06/733,360
• Time in Patent Office: 522 Days
• Field of Search: 324/77 R, 324/111, 324/112, 324/73 R, 324/73 AT, 324/57 R, 364/200, 364/508, 364/552, 364/553, 364/580, 371/20, 371/25, 370/13
• US Class Current: 324/76.22
• CPC Class Codes: G11B 20/1816 Testing
• CPC Class Codes: G11B 27/36 Monitoring, i.e. supervising the progress of recording or reproducing for digital recording G11B20/00 and s.gr.; for monitoring, testing or measuring of TV recorders of the type covered by H04N5/76 and subgroups, see H04N17/06
• CPC Class Codes: G11B 33/10 Indicating arrangements; Warning arrangements G11B15/04, G11B19/04, G11B27/34, G11B27/36 take precedence
• CPC Class Codes: H04N 17/06 for recorders

Abstract

Method and means for evaluating the quality of audio and/or video transfer characteristics of a device upon which, or through which, audio and/or video information is contained, or passes, respectively. Both method and apparatus concern the evaluation of the quality of information transfer in the recording and playing back of a recording medium or in the transferring of audio and/or video information through an information handling device referred to as a throughput device. Unit evaluation is accomplished by establishing an input signal of known content, measuring selected parameters of selected parts of the input signal, feeding the input signal to the unit under test, measuring the parameters of parts of the output signal from the unit under test corresponding to the same selected parts of the input signal, and comparing the selected parameters of the input signal with the corresponding parameters of the output signal. Whether monitoring the quality of the signal transfer characteristics of a throughput device, a magnetic tape containing program material, or a video disc, master disc or replica, a "signature" is created for the unit under test, and subsequent analysis of the unit as it progresses along a production line or of a copy made on the same or alternate recording medium results in a second "signature" which is compared against the first signature to make a determination as to the quality of the signal handling or transfer characteristics of the unit. In this manner, out-of-tolerance conditions can be automatically detected, thereby eliminating subjectivity and providing consistency in the quality level of device testing.

Claims

1. Apparatus for analyzing prescribed parameters of analog electrical signal, comprising:

(a) means for receiving a time segmented sequence of separate analog audio signals having a real time sequence rate in contiguous time segments;

each said segment containing at least one of said signals;

(b) storage means coupled to said receiving means for accumulating said signals received in real time;

(c) memory recirculating means coupled to said storage means recirculating a selected one of said segments to produce a continuous representation of the signals contained in the selected segment; and

(d) signal analyzer means coupled to said storage means for receiving said continuous representation and performing measurements thereon.

2. Apparatus for analyzing prescribed parameters of an analog electrical signal, comprising:

(a) means for receiving a series of separate analog electrical signals at a real time rate;

(b) storage mcans coupled to said receiving means for accumulating said signals received in real time;

(c) control means coupled to said storage means for serially releasing the accumulated signals from said storage means at a rate slower than said real time rate; and

(d) signal analyzer means coupled to said storage means for receiving said signal released at said slower rate and performing measurements thereon; and

wherein;

(e) said series of analog electrical signals is a sequence of signal segments, each segment containing at least one audio test tone;

(f) said means for receiving analog electrical signals comprises an analog-to-digital converter;

(g) said storage means comprises a digital memory;

(h) said apparatus further includes a digital-to-analog converter connected between said storage means and said signal analyzer means for converting said signals released at said slower rate to analog format for processing by said signal analyzer means; and

said apparatus further comprises,

(i) memory recirculating means coupled to said digital memory and connected to, and under control of, said control means for recirculating a selected one of said segments to produce at the output of said digital-to-analog converter a continuous representation of the test tone contained in the selected segment.

3. The apparatus as claimed in claim 2, wherein each said segment lasts for one-thirtieth of one second;

and said memory recirculating means recirculates said selected segment at the rate of thirty times per second to provide said continuous representation of the selected test tone.