US 6,291,948 B1Granted

Image distortion correction circuit

AssigneeMitsubishi Denki Kabushiki Kaisha

InventorsHironobu Yasui, Akinori Heishi, Yoshinori Miyamoto, Akira Ishimori, Hiroaki Nishino

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Abstract

An image distortion correction circuit is provided in which a horizontal deflection current (IH) flows through horizontal correction coils (L1, L2) and a vertical deflection current (IV) flows through either of vertical correction coils (L3, L4). The vertical correction coils (L3, L4) and the horizontal correction coils (L1, L2) are wound on the same core (4). A pair of magnets (2, 3) on opposite ends of the core (4) apply a biased magnetic field from the north pole toward the south pole. The anode of a diode (D1), the cathode of a diode (D2) and a first end of a resistor (R1) are connected to an intermediate terminal (P11) through which the vertical deflection current (IV) flows. A first end of the vertical correction coil (L3) is connected to the cathode of the diode (D1). A second end of the resistor (R1) and a terminal (P4) are connected to a second end of the vertical correction coil (L3). A first end of the vertical correction coil (L4) is connected to the terminal (P4), and a second end of the vertical correction coil (L4) is connected to the anode of the diode (D2). The image distortion correction circuit minimizes the degradation of vertical deflection sensitivity to perform an intermediate pin distortion correction.

Claims5

Dependent claims

An image distortion correction circuit comprising:

first and second horizontal correction coils in a horizontal deflection current path through which a horizontal deflection current flows, said first and second horizontal correction coils being connected in series with each other and being wound in such directions as to generate oppositely directed magnetic fields respectively;
magnetic field biasing means for biasing said magnetic fields in a first direction;
and
a vertical correction section having first and second terminals between which a vertical deflection current flows,
said vertical correction section including:
a first vertical correction coil in a first current path between said first and second terminals;
a second vertical correction coil in a second current path between said first and second terminals, said second current path being independent of said first current path;
and
a shared resistor commonly connected in parallel with said first and second current paths, wherein
said first and second current paths selectively carry said vertical deflection current of first and second polarities respectively, and
said first and second vertical correction coils generate a magnetic field in a second direction opposite from said first direction when said vertical deflection current of said first and second polarities flows through said first and second vertical correction coils respectively.

8 more elements

Dependencies are inferred from the claim text.