US4545664A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signal circuit for an automatic focusing lens
Assignee: Canon Inc
•
Filing: 1983-07-22
•
Granted: 1985-10-08
•
Expires: 2003-07-22
Abstract
Abstract A signal circuit for an automatic focusing lens is disclosed which has a displacement monitoring signal generator for generating a displacement monitoring signal representing the displacement of the lens by repeatedly turning on and off in accordance with the movement of the lens. The signal circuit is further provided with a limit signal generator for generating limit signals which represent that the lens has been moved to an infinity and a minimum-focusing-point. The displacement monitoring signal generator is connected to the limit signal generator and the output of the displacement monitoring signal is inhibited in accordance with the output of the limit signal, thereby preventing such a problem that the operation to move the lens will have been continued after the lens has been moved to the infinity or minimum-focusing-point.
Inventors
- 👤 Shinji Sakai
- 👤 Takashi Kawabata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:49
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/30; G02B7/32
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
182 words
An automatic focusing lens attachable to a camera having a focus-detection device, and adapted to move a focusing lens to a focusing position in accordance with an output from the device when said automatic focusing lens is mounted on the camera, said automatic focusing lens comprising: a focusing lens; a motor for moving said focusing lens to a focusing position in accordance with the output from the focus-detection device of the camera; and a signal circuit for terminating the movement of said focusing lens by said motor, said signal circuit comprising: monitoring means for generating a pulse-like monitoring signal in accordance with the movement of said focusing lens; output means for presenting the monitoring signal transmitted from said monitoring means to the camera side; detecting means for detecting that said focusing lens is moved to a limit location; and control means for inhibiting the transmission of said monitoring signal to said output means when said detecting means detects that said focusing leans is moved to the limit location, thereby to make the transmission of a limit signal to said output means possible,.
Claim 2
Dependent Claim
182 words
An automatic focusing lens attachable to a camera having a focus-detection device, and adapted to move a focusing lens to a focusing position in accordance with an output from the device when said automatic focusing lens is mounted on the camera, said automatic focusing lens comprising: a focusing lens; a motor for moving said focusing lens to a focusing position in accordance with the output from the focus-detection device of the camera; and a signal circuit for terminating the movement of said focusing lens by said motor, said signal circuit comprising: monitoring means for generating a pulse-like monitoring signal in accordance with the movement of said focusing lens; output means for presenting the monitoring signal transmitted from said monitoring means to the camera side; detecting means for detecting that said focusing lens is moved to a limit location; and control means for inhibiting the transmission of said monitoring signal to said output means when said detecting means detects that said focusing leans is moved to the limit location, thereby to make the transmission of a limit signal to said output means possible,.
Claim 3
Dependent Claim
49 words
An automatic focusing lens according to claim 1, wherein said automatic focusing lens comprises input means for receiving a focusing signal from the focus detection device; and focusing means for controlling the movement of said focusing lens on the basis of the focusing signal transmitted to said input means.
Claim 4
Dependent Claim
47 words
An automatic focusing lens according to claim 2, wherein said automatic focusing lens comprises inhibiting means for inhibiting the transmission of the focusing signal from said input means to said focusing means when said detecting means detects that said focusing lens is moved to a limit location.
Claim 5
Dependent Claim
32 words
An automatic focusing lens according to claim 3, wherein said detecting means respectively detects that said focusing lens is moved to the limit locations respectively corresponding to an infinity and a minimum-focusing-point.
Claim 6
Dependent Claim
140 words
A signal circuit for an automatic focusing lens attachable to a camera having a focus-detection device, and adapted to move a focusing lens to a focusing position in accordance with an output from the device when the automatic focusing lens is mounted on the camera, said signal circuit comprising: monitoring means for generating a pulse-like monitoring signal in accordance with the movement of the focusing lens; output means for presenting the monitoring signal transmitted from said monitoring means to the camera side; detecting means for detecting that the focusing lens is moved to a limit location; and control means for inhibiting the transmission of said monitoring signal to said output means when said detecting means detects that the focusing lens is moved to the limit location, thereby to make the transmission of a limit signal to said output means possible.
Claim 7
Dependent Claim
140 words
A signal circuit for an automatic focusing lens attachable to a camera having a focus-detection device, and adapted to move a focusing lens to a focusing position in accordance with an output from the device when the automatic focusing lens is mounted on the camera, said signal circuit comprising: monitoring means for generating a pulse-like monitoring signal in accordance with the movement of the focusing lens; output means for presenting the monitoring signal transmitted from said monitoring means to the camera side; detecting means for detecting that the focusing lens is moved to a limit location; and control means for inhibiting the transmission of said monitoring signal to said output means when said detecting means detects that the focusing lens is moved to the limit location, thereby to make the transmission of a limit signal to said output means possible.
Claim 8
Dependent Claim
47 words
A signal circuit according to claim 5, wherein said signal circuit comprises input means for receiving a focusing signal from the focus detection device; and focusing means for controlling the movement of the focusing signal on the basis of the focusing signal transmitted to said input means.
Claim 9
Dependent Claim
45 words
A signal circuit according to claim 6, wherein said signal circuit comprises inhibiting means for inhibiting the transmission of the focusing signal from said input means to the focusing means when said detecting means detects that the focusing lens is moved to a limit location.
Claim 10
Dependent Claim
31 words
A signal circuit according to claim 7, wherein said detecting means respectively detects that the focusing lens is moved to the limit locations respectively corresponding to an infinity and a minimum-focusing-point.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-10-07 | 1989-04-08 | 1989-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-07 | 1993-04-08 | 1993-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-07 | 1997-04-08 | 1997-10-08 | $7700.00 | Window Closed / Lapsed |