Image stabilization control circuit

• US 7,760,448 B2
• Filed: 12/08/2008
• Issued: 07/20/2010
• Est. Priority Date: 12/25/2007
• Status: Active Grant

• Current Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Original Assignee: Sanyo Semiconductor Company Limited (ON Semiconductor Corporation), Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Yamada, Yasuhisa, Tashita, Yuuki, Nagata, Yasunori
• Primary Examiner(s): HASAN, MOHAMMED A
• Application Number:
  US12/314,306
• Publication Number:
  US 20090161237A1
• Time in Patent Office: 589 Days
• Field of Search: 359/814, 359/811, 359721-727, 348/208.99, 348/208.6, 348/252, 348/345, 348/352, 348/700, 396/54, 396/55
• US Class Current: 359/814
• CPC Class Codes: G03B 5/00 Adjustment of optical system relative to image or object surface other than for focusing

Abstract

A image stabilization control circuit for an image capturing device, wherein a gyro-equalizer (24) integrates an angular velocity signal from a gyro-sensor (12) in an integration circuit (46). The integration circuit (46) is composed of a low-boost filter (LBF), and a phase delay in a target compensation region is set to a value appropriate for an integration process. Furthermore, a characteristic whereby the LBF reduces the phase delay at higher frequencies is used, compensation is applied to the excess phase delay of the angular signal in the high-frequency region brought about by the effect of the phase delay generated in the high-frequency region by the output signal of the gyro-sensor (12), and the phase delay in the high-frequency region is brought nearer to 90 degrees. This allows the accuracy of the process for determining the required displacement magnitude of a lens to be increased.

Claims

1. A image stabilization control circuit in which a vibration detection signal corresponding to the movement speed of an image capturing device is obtained from a vibration detector provided to the image capturing device, and which drives a vibration compensation mechanism of the image capturing device, the image stabilization control circuit comprising:

a vibration-compensating signal generator circuit for performing an integration process on the vibration detection signal and generating a vibration-compensating signal corresponding to the displacement magnitude of the image capturing device; and

a servo-circuit for generating, on the basis of the vibration-compensating signal, a drive signal for driving the vibration-compensating mechanism;

wherein the vibration-compensating signal generator circuit has;

a high pass filter for damping a low-frequency component from the vibration detection signal, and transmitting a vibration component of the target compensation region; and

an integration circuit for performing the integration process on the vibration detection signal transmitted by the high pass filter; and

wherein the integration circuit uses a phase delay compensation circuit for compensating a phase delay in the target compensation region, achieves a counterbalance between a reduced phase delay of the phase delay compensation circuit in a high-frequency region, and a phase delay of the vibration detection signal increased in the high-frequency region by the characteristics of the vibration detector, and adjusts the phase characteristics in the target compensation region and the high-frequency region.

2. The image stabilization control circuit of claim 1, wherein:

the phase delay compensation circuit constituting the integration circuit is a low-boost filter.

3. The image stabilization control circuit of claim 1, wherein:

the servo-circuit generates the drive signal on the basis of a signal that is a sum of a signal corresponding to a drive magnitude of the vibration compensation mechanism obtained from a drive magnitude detector provided to the image capturing device, and the vibration-compensating signal outputted from the vibration-compensating signal generator circuit.

4. The image stabilization control circuit of claim 1, wherein:

the vibration-compensating signal generator circuit has a centering high-pass filter for damping a direct-current component from the output signal of the integration circuit.

5. The image stabilization control circuit of claim 1, wherein:

the high-pass filter and the integration circuit include a digital filter circuit and a register; and

the digital filter circuit performs a filtering process on the basis of a filter factor stored in the register.

6. The image stabilization control circuit of claim 4, wherein:

the high-pass filter, the integration circuit, and the centering high-pass filter include a digital filter circuit and a register; and

the digital filter circuit performs a filtering process on the basis of a filter factor stored is the register.