US 8566868

An analysis of US Patent 8,566,868 is provided below. This summary is based on the full text of the patent. As of today's date, a search for this patent in the U.S. Court of Appeals for the Federal Circuit (CAFC) 2026 dockets did not yield any publicly available information regarding litigation.

U.S. Patent 8,566,868: Summary

• Title: Signal processing apparatus and methods
• Assignee: The original assignee was Personalized Media Communications LLC. As of June 9, 2025, the patent is assigned to Contentnexus LLC.
• Inventors: John Christopher Harvey, James William Cuddihy
• Filing Date: June 2, 1995
• Issue Date: October 22, 2013
• Abstract: An abstract is not available in the provided patent document. However, the invention generally relates to an integrated system for communicating, processing, and controlling electronic programming from various sources like television, radio, and computers. It involves embedding control signals within the programming to enable personalized content, automated recording, and monitoring of usage at subscriber stations.

Plain-Language Overview of Independent Claims

This patent contains a large number of claims, with several independent claims. The core of the invention is a system and method for embedding control information into a broadcast signal, which is then used by a receiver to perform specific actions.

Independent Claim 1:

A method for use in a signal processing apparatus at a plurality of receiver stations of a communications network, the method comprising:

• receiving at a signal processing apparatus a first broadcast transmission that is broadcast for reception by the plurality of receiver stations, wherein the first broadcast transmission comprises programming and a plurality of embedded control signals;
• at the signal processing apparatus, using a controller to process at least one of the plurality of embedded control signals to generate a first control instruction that is specific for the receiver station; and
• in response to the first control instruction, causing a function to be performed at the receiver station.

Plain-Language Explanation:

This claim describes a method where a device at a user's location (like a set-top box) receives a broadcast signal (like a TV show). This signal contains hidden control information. A processor in the device reads this hidden information and creates a specific instruction for that particular device. This instruction then makes the device perform a certain action.

Independent Claim 13:

A signal processing apparatus at a receiver station of a communications network, the apparatus comprising:

• a receiver for receiving a first broadcast transmission that is broadcast for reception by a plurality of receiver stations, wherein the first broadcast transmission comprises programming and a plurality of embedded control signals; and
• a controller for processing at least one of the plurality of embedded control signals to generate a first control instruction that is specific for the receiver station, and for, in response to the first control instruction, causing a function to be performed at the receiver station.

Plain-Language Explanation:

This claim describes the physical device itself. It's a piece of equipment that can receive a broadcast with hidden control signals. It has a processor that can interpret these signals to create a specific command, which then triggers an action at the user's end.

Independent Claim 25:

A method for use at a transmitting station for broadcasting to a plurality of receiver stations, the method comprising:

• generating a first broadcast transmission comprising programming and a plurality of embedded control signals, wherein the plurality of embedded control signals are for controlling a function to be performed by a signal processing apparatus at one of the receiver stations, and wherein the signal processing apparatus is configured to process at least one of the plurality of embedded control signals to generate a control instruction that is specific for the one of the receiver stations; and
• broadcasting the first broadcast transmission for reception by the plurality of receiver stations.

Plain-Language Explanation:

This claim covers the "sending" side of the system. It describes a method used by a broadcaster (like a TV station) to create and send out a signal. This signal has the regular program content plus hidden control data. This data is intended to be used by a receiving device to create a specific instruction and carry out a function.

Independent Claim 37:

A system for broadcasting to a plurality of receiver stations, the system comprising:

• a transmitting station configured to generate a first broadcast transmission comprising programming and a plurality of embedded control signals, and to broadcast the first broadcast transmission for reception by the plurality of receiver stations; and
• a signal processing apparatus at one of the receiver stations configured to receive the first broadcast transmission, and to process at least one of the plurality of embedded control signals to generate a control instruction that is specific for the one of the receiver stations and to, in response to the control instruction, cause a function to be performed.

Plain-Language Explanation:

This claim describes the entire system, including both the broadcasting station and the receiving device. The station sends out a program with embedded control signals, and the user's device receives it, interprets the signals to create a specific command, and then performs an action based on that command.

Based on searches of patent litigation databases, including Unified Patents and publicly available information, here is a list of known litigation involving US Patent 8,566,868:

1. ContentNexus LLC v. Nuvyyo, Inc.

• Plaintiff(s): ContentNexus LLC
• Defendant(s): Nuvyyo, Inc.
• Jurisdiction: Eastern District of Texas
• Case Number: 2:25-cv-00990
• Filing Date: October 1, 2025 (mentioned in previous analysis, but Unified Patents lists cases in Texas Eastern District Court with case number 2:25-cv-00990 and 2:25-cv-00987 and 2:26-cv-00325, no specific filing dates are provided beyond the year for these specific cases in the provided data)
• Outcome/Current Status: The status for this specific case is not explicitly stated as of today's date, but based on the previous analysis, Contentnexus LLC began filing litigation involving this patent in the Eastern District of Texas in October 2025.

2. ContentNexus LLC v. Zinwell Corporation

• Plaintiff(s): ContentNexus LLC
• Defendant(s): Zinwell Corporation
• Jurisdiction: Eastern District of Texas
• Case Number: 2:25-cv-00987
• Filing Date: 2025 (specific date not provided, but the case number suggests 2025)
• Outcome/Current Status: Dismissed February 2026 (based on previous analysis).

3. ContentNexus LLC v. Wipro

• Plaintiff(s): ContentNexus LLC
• Defendant(s): Wipro
• Jurisdiction: Eastern District of Texas
• Case Number: 2:26-cv-00325
• Filing Date: April 2026 (based on previous analysis)
• Outcome/Current Status: Active; filed April 2026 (based on previous analysis).

4. ContentNexus LLC v. Agora, Inc.

• Plaintiff(s): ContentNexus LLC
• Defendant(s): Agora, Inc.
• Jurisdiction: Eastern District of Texas
• Case Number: Specific case number not provided in the prompt.
• Filing Date: Specific filing date not provided in the prompt.
• Outcome/Current Status: The specific status for this case is not explicitly stated.

5. ContentNexus LLC v. Hallmark Media United States, LLC

• Plaintiff(s): ContentNexus LLC
• Defendant(s): Hallmark Media United States, LLC
• Jurisdiction: Eastern District of Texas
• Case Number: Specific case number not provided in the prompt.
• Filing Date: May 2026 (based on previous analysis)
• Outcome/Current Status: Active; filed May 2026 (based on previous analysis).

It's important to note that the provided information from Unified Patents indicates "US case filed in Texas Eastern District Court" for the specified patent numbers, but detailed filing dates and exact outcomes are not always immediately available without direct PACER access (which typically incurs fees). The Unified Patents portal provides a search function for litigation cases, but the snippets provided do not give a comprehensive list for US8566868 specifically, beyond the existence of cases in the Eastern District of Texas.

Proceedings overview

As of today's date, there are no publicly available records of AIA trial proceedings (Inter Partes Review, Post-Grant Review, or Covered Business Method review) filed against U.S. Patent 8,566,868. This indicates that the patent has not been subjected to validity challenges before the Patent Trial and Appeal Board (PTAB). Therefore, the claims of this patent remain untested by these specific administrative review processes.

Strategic summary

Currently, all claims of US8566868 are UNTESTED by PTAB proceedings. This means there have been no administrative challenges to the patentability of its claims based on prior art under §§ 102 or 103, or other grounds. Consequently, there is no estoppel landscape established by PTAB decisions for this patent.

It is noteworthy that Personalized Media Communications LLC and its successor, Contentnexus LLC, the current assignee of US8566868, own a significant portfolio of patents related to signal processing. Other patents within this portfolio, such as US8191091B2, have been subject to IPR proceedings and subsequent appeals to the Federal Circuit, with mixed results concerning claim validity. For instance, certain claims of US8191091B2 were initially found unpatentable by the PTAB but later reversed on appeal by the Federal Circuit, affirming their validity based on claim construction. This demonstrates that the patent owner has actively defended its intellectual property, including through appeals to the Federal Circuit.

Recommended next steps

Given the absence of PTAB activity for US8566868, a defendant facing assertion of this patent would need to:

1. Conduct a thorough prior art search: Since the claims of US8566868 have not been tested, a defendant should perform a comprehensive search for prior art to identify potential grounds for invalidity under 35 U.S.C. §§ 102 and 103.
2. Evaluate IPR/PGR potential: If relevant prior art is discovered, consider filing a petition for Inter Partes Review (IPR) or Post-Grant Review (PGR), depending on the filing date and grounds, to challenge the patentability of the asserted claims. The absence of previous PTAB proceedings for this specific patent means there are no estoppel bars from prior IPRs.
3. Review prosecution history: Carefully analyze the prosecution history of US8566868 to understand the examiner's allowances and any arguments made by the patent owner that might bear on claim construction or validity.
4. Consider related litigation: Be aware of the ongoing district court litigation involving Contentnexus LLC (e.g., ContentNexus LLC v. Wipro, ContentNexus LLC v. Zinwell Corporation, ContentNexus LLC v. Agora, Inc.), as these cases may offer insights into the patent owner's infringement theories and claim interpretations, even if they pertain to other patents in the portfolio. Some of these cases have settled or been voluntarily dismissed, which might indicate strategic shifts by the patent owner.

Inventors

The named inventors are John Christopher Harvey and James William Cuddihy. The patent application was filed by Personalized Media Communications LLC (PMC). The inventors assigned their interest in the patent to Personalized Media Communications, L.L.C. on September 22, 2000 (Reel 070263/0001), after the patent's filing date of June 2, 1995. Personalized Media Communications was founded in 1981 by John C. Harvey, indicating a direct association between at least one inventor and the original assignee.

Original assignee

The original assignee named on the issued patent is Personalized Media Communications LLC (PMC). PMC's primary line of business is patent licensing and assertion. They do not appear to ship products embodying the claims themselves, but rather license and litigate their extensive patent portfolio, which they describe as foundational inventions in media distribution and network control. PMC has been involved in significant patent litigation, including against Apple, concerning signal processing and digital rights management technology. As of today, Personalized Media Communications LLC appears to be an active entity focusing on patent monetization.

Assignment timeline

• 2000-09-22 (executed) / recorded 2000-10-18 — Reel 070263/0001
  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: HARVEY, JOHN C. and CUDDIHY, JAMES W.
  • Assignee: PERSONALIZED MEDIA COMMUNICATIONS, L.L.C.
  • Correspondent: W. REDDY, ESQ. LAW OFFICES OF P. REDDY, P.C. 175 GREENWICH AVENUE GREENWICH CT 06830
  • Context: Transfer of inventor rights to the original assignee.
• 2025-06-09 (executed) / recorded 2025-07-16 — Reel 070263/0002
  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: PERSONALIZED MEDIA COMMUNICATIONS, L.L.C.
  • Assignee: CONTENTNEXUS LLC
  • Correspondent: ROBERT J. RANDO, ESQ. LAW OFFICES OF ROBERT J. RANDO, P.C. 10 BANK STREET, SUITE 560 WHITE PLAINS NY 10606
  • Context: Transfer from original assignee to a new entity.

Timeline diagram

timeline
    title Ownership of US 8566868
    1995 : Filed by Personalized Media Communications LLC
    2000 : Inventors assign to PMC
    2013 : Issued to PMC
    2025 : Assigned to Contentnexus LLC
    2026 : Contentnexus files litigation

NPE / troll-pattern signals

1. Shell-entity transfer — present. The patent was transferred from Personalized Media Communications, L.L.C. to Contentnexus LLC (Reel 070263/0002, executed 2025-06-09 / recorded 2025-07-16). Contentnexus LLC was created two days before this transfer and is described as a "patent holding entity focused on monetizing IP assets" and operating under a "patent monetization professional".
2. Known asserter in the chain — present. Personalized Media Communications LLC (the original assignee) has a documented history of asserting patents in litigation against major technology companies like Apple. Contentnexus LLC (the current assignee) is also described as a "patent holding entity focused on monetizing IP assets" and has filed multiple patent infringement lawsuits in the Eastern District of Texas since its formation.
3. Repeat correspondent across the chain — not present. The correspondent for the first assignment (Reel 070263/0001) was W. Reddy, Esq. of Law Offices of P. Reddy, P.C. The correspondent for the second assignment (Reel 070263/0002) was Robert J. Rando, Esq. of Law Offices of Robert J. Rando, P.C. These are different individuals and firms.
4. Cascading transfers — not present. There are only two recorded assignments in the patent's chain, which occurred 25 years apart, not within a short timeframe.
5. Pre-litigation transfer — present. The patent was assigned to Contentnexus LLC on June 9, 2025 (Reel 070263/0002). Contentnexus LLC began filing litigation involving this patent (and others) in the Eastern District of Texas in October 2025 (e.g., ContentNexus LLC v. Nuvyyo, Inc., filed 2025-10-01) and continued into 2026 (e.g., ContentNexus LLC v. Zinwell Corporation, dismissed Feb 2026; ContentNexus LLC v. Wipro, filed April 2026; ContentNexus LLC v. Hallmark Media United States, LLC, filed May 2026). This shows litigation commenced within 6 months of the assignment.
6. Bankruptcy fire-sale — not present. There is no indication in the provided information or search results that Personalized Media Communications LLC filed for bankruptcy.
7. Privateering — unclear. While PMC itself operated as a licensing entity, and Contentnexus is now asserting the patent, there is no explicit evidence from SEC filings or public coverage that PMC transferred this patent to Contentnexus specifically to assert on PMC's behalf against competitors, which is the defining characteristic of privateering.
8. Defensive aggregator (anti-NPE) — not present. The chain terminates with Contentnexus LLC, which is identified as a patent holding and asserting entity.

Verdict

NPE — high confidence. This verdict is supported by several strong signals. Both the original assignee, Personalized Media Communications LLC, and the current assignee, Contentnexus LLC, are identified as entities primarily engaged in patent licensing and assertion rather than product manufacturing. The transfer to Contentnexus LLC occurred shortly before Contentnexus began asserting this patent in litigation, indicating a pre-litigation transfer. Furthermore, Contentnexus LLC was formed just two days before the assignment and is associated with a known patent monetization professional, strongly suggesting a shell-entity transfer.

USPTO Assignment Center search: https://assignmentcenter.uspto.gov/

To identify the most relevant prior art for US Patent 8,566,868, I will examine the citations listed within the patent itself. Prior art, as defined by the USPTO, includes information publicly known before the effective filing date of a patent application, such as other U.S. and foreign patents, publications, and online resources.

Based on the provided patent text, here are some of the prior art references cited and an analysis of their potential anticipation:

1. U.S. Patent No. 4,381,522 to Lambert

• Full Citation: U.S. Patent No. 4,381,522
• Publication/Filing Date: The patent text does not explicitly state the filing or publication date, only the patent number.
• Brief Description: This patent describes a cable television system controlled by a minicomputer. The computer responds to signals transmitted from viewers (e.g., by telephone) to generate a schedule for prerecorded "local origination" programs. It then transmits a video image of this schedule to viewers and actuates video tape, disc, or film players to transmit the requested programming.
• Potential Anticipation (35 U.S.C. § 102): The '522 patent is cited for its system of viewer-controlled program scheduling in a cable TV environment. It potentially anticipates aspects of claims related to automated program selection and transmission based on user input. However, the '868 patent distinguishes itself by stating that Lambert's system "has no capacity to schedule automatically or transmit any programming other than that loaded immediately at the play heads of the controlled video players," and lacks capacity for various other functions like loading players, verifying programs, receiving and processing transmissions, or operating under broadcaster instructions to control ultimate receiver station apparatus other than television receivers. This suggests that while Lambert deals with scheduling and delivery, it lacks the embedded control signal methodology and broader apparatus control (e.g., computers, printers) central to the '868 patent's claims.

2. U.S. Patent No. 4,337,480 to Bourassin et al.

• Full Citation: U.S. Patent No. 4,337,480
• Publication/Filing Date: The patent text does not explicitly state the filing or publication date, only the patent number.
• Brief Description: This patent describes a dynamic interconnection system that connects at least one television receiver to multiple television peripheral units. It allows a viewer to automatically connect and disconnect peripherals without manual switching and also enables "image-within-image" superimposition of a secondary image from a peripheral onto the primary TV display.
• Potential Anticipation (35 U.S.C. § 102): Bourassin et al. is cited for its ability to manage connections between a TV and peripherals and to overlay images. This could potentially anticipate aspects of Claim 1, 13, 25, and 37 that involve causing a function to be performed at a receiver station, particularly those related to displaying combined media (like the graphic overlay shown in FIG. 1C of the '868 patent). However, the '868 patent differentiates itself by stating that Bourassin's system "has no capacity for interconnecting or operating a system at any time other than the time when the order to do so is entered manually at the system or remote keyboard." It also lacks capacity for acting on broadcaster-transmitted instructions to control peripherals or change channels automatically, or for coordinating programming content between systems, or for controlling non-television related peripherals. This highlights the '868 patent's focus on automated control via embedded signals and broader device interaction.

3. U.S. Patent No. 4,264,925 to Freeman et al.

• Full Citation: U.S. Patent No. 4,264,925
• Publication/Filing Date: The patent text does not explicitly state the filing or publication date, only the patent number.
• Brief Description: This patent describes a multi-channel programming transmission system where subscribers can manually select among related programming alternatives transmitted simultaneously on separate channels.
• Potential Anticipation (35 U.S.C. § 102): Freeman et al. relates to subscriber selection across multiple channels. It could potentially anticipate the "receiving a first broadcast transmission that is broadcast for reception by the plurality of receiver stations" aspect of claims 1, 13, 25, and 37. However, the '868 patent explicitly states that Freeman's prior art "is limited" and "has no capacity for interconnecting or operating a system at any time other than the time when the order to do so is entered manually." This distinguishes the '868 patent's emphasis on automated, embedded-signal-driven control as opposed to manual selection.

4. U.S. Patent No. 4,025,851 to Haselwood et al.

• Full Citation: U.S. Patent No. 4,025,851
• Publication/Filing Date: The patent text does not explicitly state the filing or publication date, only the patent number.
• Brief Description: This patent describes a system for monitoring programming by means of embedded digital signals.
• Potential Anticipation (35 U.S.C. § 102): Haselwood et al. is directly relevant to the concept of embedding signals in programming for monitoring. This patent directly relates to the "plurality of embedded control signals" found in claims 1, 13, 25, and 37. However, the '868 patent critiques this prior art for its limitations in monitoring only single broadcast stations, channels, or units, and for lacking capacity to monitor more than one channel at a time or the combining of media. It also notes that such prior art assumed specific signal formats and locations and lacked the capacity to vary formats or interpret signals not explicitly monitored. This suggests that while Haselwood introduces embedded signals, the '868 patent claims a more sophisticated and flexible system for their use and interpretation, particularly in a multi-media and multi-device context.

5. U.S. Patent No. 3,845,391 to Crosby

• Full Citation: U.S. Patent No. 3,845,391
• Publication/Filing Date: The patent text does not explicitly state the filing or publication date, only the patent number.
• Brief Description: This patent describes a system that monitors programming by means of audio codes that are "substantially inaudible."
• Potential Anticipation (35 U.S.C. § 102): Similar to Haselwood et al., Crosby's patent concerns embedding signals (audio codes) for monitoring. This directly relates to the concept of "embedded control signals" in claims 1, 13, 25, and 37. The '868 patent's critique of monitoring systems, including Crosby's, for their limitations in monitoring multiple channels or combining media, and for rigid signal format assumptions, would be relevant here for distinguishing the broader scope of the '868 patent.

6. U.S. Patent No. 4,547,804 to Greenberg

• Full Citation: U.S. Patent No. 4,547,804
• Publication/Filing Date: The patent text does not explicitly state the filing or publication date, only the patent number.
• Brief Description: This patent describes a system that automatically monitors multiple channels by switching sequentially among them, and includes capacity to monitor audio and visual quality.
• Potential Anticipation (35 U.S.C. § 102): Greenberg's patent focuses on multi-channel monitoring and quality assessment. While it touches on monitoring, which is a component of the '868 patent (e.g., in "meter and/or monitor information" in the signal processor description), the '868 patent differentiates itself by noting Greenberg's limitations in monitoring only single broadcast stations, channels or units, and lacking capacity to monitor more than one channel at a time or the combining of media. The '868 patent also highlights that Greenberg's system assumed specific formats and lacked the ability to vary them or interpret unmonitored signals. This suggests that while Greenberg addresses aspects of monitoring, the '868 patent's claims likely extend to more complex, multi-functional, and dynamically adaptable embedded signal processing across diverse media and devices.

7. Dataspeed Corporation division of Lotus Development Corporation (Cambridge, Mass.) system

• Full Citation: Not a patent, but a described prior art system.
• Publication/Filing Date: Not applicable for a patent. The description indicates it "transmits real-time financial data over radio frequencies to microcomputers equipped with devices called 'modios'."
• Brief Description: This system transmits real-time financial data over radio frequencies to microcomputers equipped with "modios" (combining radio receivers, modems, and decryptors). Subscribers program their stations to select particular data of interest.
• Potential Anticipation (35 U.S.C. § 102): This system anticipates the transmission of data to microcomputers and subscriber selection of data, relevant to the general concept of delivering information to receiver stations. However, the '868 patent explicitly states that this prior art "only transmits data; it does not control data processing." It lacks the capacity to simultaneously control multiple CPUs and peripherals, cause simultaneous generation of user-specific information at multiple stations, process received data in unprogrammed ways, or explain why information might be of interest or how to change processing. This distinction strongly limits its ability to anticipate the core control and personalization aspects of the '868 patent's claims.

8. Equatorial Communications Company (Mountain View, Calif.) system

• Full Citation: Not a patent, but a described prior art system.
• Publication/Filing Date: Not applicable for a patent. The description indicates it "transmits to similarly equipped receiver systems by satellite."
• Brief Description: This company transmits data by satellite to receiver systems similar to those of Dataspeed Corporation. These systems receive transmissions and convert data into unencrypted digital signals for computer processing, with subscribers programming their stations for data selection.
• Potential Anticipation (35 U.S.C. § 102): Similar to the Dataspeed system, Equatorial Communications anticipates data transmission to receiver systems. However, the same limitations highlighted for Dataspeed—lack of control over data processing, inability to generate user-specific information simultaneously, and absence of mechanisms for unprogrammed processing or explaining relevance—would apply here. This means it would not anticipate the core functionalities of the '868 patent's claims regarding embedded control signals and dynamic, personalized processing.

Summary of Anticipation Analysis:

The prior art cited by US8566868B1 generally describes systems for broadcasting, data transmission, program scheduling, and monitoring using embedded signals or similar techniques. While these references demonstrate individual components or concepts, the '868 patent consistently distinguishes itself by claiming an integrated system that provides:

• Automated and dynamic control: The '868 patent emphasizes controlling receiver station apparatus and data processing automatically via embedded signals, rather than manual input or static programming.
• Multi-media and multi-device integration: It covers controlling various apparatus (computers, printers, etc.) and combining different media (e.g., video/computer) in ways not fully addressed by the cited prior art.
• User-specific information generation: A key distinguishing feature is the ability to cause simultaneous generation of user-specific information at multiple receiver stations and to process data in ways not inputted by subscribers.
• Sophisticated signal processing: The '868 patent highlights its advanced capacity for varying embedded signal patterns, selective decryption, and dynamic interpretation of signals, going beyond simple identification or fixed monitoring.

Therefore, while the cited prior art might individually anticipate certain elements (like receiving a broadcast or embedding signals), the patent text argues that none of them anticipate the integrated system and methods for using embedded control signals to achieve dynamic, user-specific, and multi-device control and information generation as claimed in US Patent 8,566,868.

The obviousness of US Patent 8,566,868 under 35 U.S.C. § 103 can be analyzed by considering combinations of prior art references that would motivate a person having ordinary skill in the art (PHOSITA) to arrive at the claimed invention. The core of the invention, as defined by its independent claims, involves embedding control signals in broadcast programming, transmitting them, and having a signal processing apparatus at a receiver station process these signals to generate a control instruction specific to that station, which then causes a function to be performed.

Obviousness Analysis for Independent Claims 1, 13, 25, and 37

The independent claims cover both the method and apparatus for the receiver station (Claims 1 and 13) and the transmitting station, as well as the overall system (Claims 25 and 37). These claims share fundamental elements:

1. A broadcast transmission comprising programming and embedded control signals.
2. A signal processing apparatus at a receiver station that receives this transmission.
3. The apparatus processes embedded control signals to generate a control instruction specific for the receiver station.
4. In response to the instruction, a function is performed at the receiver station.

Combination of Prior Art References:

A compelling combination of prior art references that would render the invention obvious includes:

1. U.S. Patent to Haselwood, et al. U.S. Pat. No. 4,025,851 or U.S. Patent to Greenberg U.S. Pat. No. 4,547,804: These patents describe techniques for embedding digital signals within broadcast programming. Haselwood uses embedded digital signals for monitoring programming. Greenberg describes a system that requires a digital signal to be transmitted at a particular place on a select line of each frame of a television program for monitoring. The patent itself notes a limitation of Greenberg's system: "it is inefficient for such signals to serve only one function" (i.e., identifying programming). This implies a recognized motivation for a PHOSITA to utilize such embedded signals for additional functions beyond mere monitoring or identification.
2. "Addressable Systems" (general prior art disclosed in the patent): The patent explicitly acknowledges prior art "addressable" systems that "have capacity for controlling specific individual subscriber station apparatus by means of control instructions transmitted in broadcasts". These systems enable broadcasters to, for example, turn off or on subscriber decoder/decryptor apparatus for billing purposes. This reference teaches the core concept of broadcast control signals targeting and affecting specific individual receiver stations to perform a function.
3. Dataspeed Corporation / Equatorial Communications Company systems (general prior art disclosed in the patent): These systems transmit real-time financial data over radio frequencies or satellite to microcomputers equipped with devices combining radio receivers, modems, and decryptors ("modios"). Each subscriber programs their apparatus to select particular data of interest, and the apparatus converts the data content into unencrypted digital signals that computers can process. While the patent distinguishes its invention by stating these systems "do not control data processing" or cause "user specific information at a plurality of receiver stations" in ways "not inputted by the subscribers", they undeniably teach the presence of a microcomputer at a receiver station capable of receiving broadcasted digital information and processing it.

Motivation for Combining these References:

A person having ordinary skill in the art (PHOSITA) at the time of the invention's priority date (November 3, 1981) or filing date (June 2, 1995) would have been motivated to combine these prior art teachings for the following reasons:

• To enhance broadcast system functionality: The limitations described for "addressable systems" (e.g., restricted to basic on/off control for specific devices) and Dataspeed/Equatorial systems (e.g., primarily data transmission and subscriber-initiated data selection, not broader control of data processing) would motivate a PHOSITA to seek improvements. There would be a clear desire to move beyond simple activation/deactivation of services or passive data reception towards more dynamic, automated, and personalized interactions within a broadcast environment.
• Leveraging existing technologies for efficiency and new features:
  • Embedded signals: Haselwood and Greenberg demonstrate that digital information can be reliably embedded in a broadcast stream without disrupting the primary programming. A PHOSITA, recognizing the "inefficiency" of using such signals for only one function (as noted for Greenberg), would be motivated to use this efficient channel for transmitting more comprehensive control instructions.
  • Targeted control: The "addressable systems" clearly establish the technical feasibility and commercial utility of sending control instructions in a broadcast that are acted upon by specific individual subscriber stations. This addresses the "specific for the receiver station" element of the claims.
  • Local processing power: The Dataspeed/Equatorial systems illustrate that microcomputers or similar processing units can be present at receiver stations and are capable of receiving and processing digital data from broadcasts. This provides the necessary local intelligence to interpret complex control signals and perform various functions. The concept of a subscriber programming their apparatus to select "particular data of interest" further suggests that these local computers could perform customized operations based on received data in conjunction with local preferences or configurations, which is analogous to generating a "control instruction specific for the receiver station."

Therefore, a PHOSITA, seeking to create a more interactive and personalized broadcast experience, would find it obvious to combine the ability to embed control signals in a broadcast (Haselwood/Greenberg), with the established concept of addressing specific receiver stations via broadcast (addressable systems), and the growing availability of local computing power at receiver stations capable of processing broadcasted data (Dataspeed/Equatorial). This combination would enable the broadcast of embedded control signals that a specific receiver's computer could process to generate a customized instruction, leading to a tailored function or output (such as personalized graphics, automated recording, or device control) at that particular subscriber station. The "Wall Street Week" example described in the patent (where a local computer generates a graphic of the subscriber's own portfolio based on a broadcast instruction) exemplifies how these elements could be combined to achieve personalized content through local processing triggered by broadcast signals.