JPS6096080A - Image pickup device - Google Patents

Abstract

PURPOSE:To grasp a proper shape of an object and a position, and to increase accuracy of monitoring by obtaining plural-light spectrum band signals which are converted to electrical signals through one image pickup lens, focusing either of these signals, and switching the focus for the generation source of the signal when a specific signal, which is determined beforehand, is detected. CONSTITUTION:For example, when a fire breaks out, a light signal of a wavelength lambda1, which corresponds to the fire, is overlapped to an incident light, and an output 5 of an amplifier 4 becomes both lambda1 and lambda2 signals. This output 5 is added to a lambda1 light-image signal extracting circuit 5 and a lambda2 light-image signal extracting circuit 9. In the lambda1 light-image signal extracting circuit 5, the lambda1 signal corresponding to the fire is extracted and the signal is added to a focus adjusting circuit 12 through a switching circuit 11. Therefore, an image pickup lens 2 corresponds to the lambda1 signal which is added to the focus adjusting circuit 12, and the lens is focused to the fire source which is a source of the lambda1 signal. On the other hand, the lambda2 signal which is extracted at the lambda2 light-image signal extracting circuit 9, and a lambda1 signal 7 from a lambda1 light-image signal extracting circuit 6 are displayed on a monitoring television 10.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an imaging device that automatically adjusts the focus of an imaging lens.

Conventional configurations and their problems Image monitoring methods using television cameras and monitor televisions have been widely used in the fields of crime prevention and disaster prevention in recent years. Cameras that adjust the image focus are becoming popular.

In this case, the focus is adjusted using the camera output signal, so even if an object to be monitored occurs depending on the camera's field of view, the effect of that object on the camera output is small and the focus can be adjusted to the object in a concentrated manner. There were times when I was unable to do so.

Therefore, the object to be monitored may be blurred, which is a disadvantage in terms of image monitoring.

Purpose of the Invention The present invention is an imaging method which, when an object to be monitored occurs, focuses on the image of the object, accurately grasps the shape and position of the object, and improves the accuracy of monitoring. It is a device.

Structure of the Invention ゛The present invention obtains a plurality of different optical spectrum band signals converted into electrical signals through one imaging lens, focuses on one of these signals, and selects a predetermined specific signal. This imaging device switches its focus to the source of the signal when it detects the signal.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an embodiment in which the present invention is applied to fire detection. Incident light 1 from a subject enters an imaging lens 2, focuses on a target of a sensor 3 such as a pyroelectric image tube, converts an infrared light image in the incident light 1 into an electrical signal, and converts the infrared light image into an electrical signal by an amplifier 4. Amplify.

In the sensor 3, as shown in FIG. 2, a stripe filter 30 is arranged perpendicular to the optical axis, in which stripes 32, 33 that transmit light wavelengths λ1 and λ2, and stripes 34' and 35 that transmit only λ1 are arranged in sequence. . Figure 3 shows λ1
．． Spectral characteristics around the λ2 wavelength are shown.

If the sensor 3 has a two-dimensional spread, the light image incident on the imaging lens 2 will be separated into λ1 images by the circuit system through the stripe filter 30 shown in FIG.
The signal 5 in the figure is converted to λ1 consisting of a bandpass filter and a detection circuit.
The optical image signal extraction circuit 6 extracts the λ1 optical image, and the output signal 8 is applied to one input terminal of the image signal switching circuit 11.

- The force output signal 5 is further applied to a λ2 optical signal extraction circuit 9, and a λ2 optical image is extracted. The λ2 optical signal extraction circuit 9 may have the same configuration as the λ1 optical signal extraction circuit 6. The obtained λ2 optical image is reproduced on the monitor television 10 and simultaneously applied to the other input terminal of the image signal switching circuit 11. The output of the image signal switching circuit 11 is applied to the focus adjustment circuit 12. 13 is a synchronization signal input.

When there is no fire, the incident light 1 does not include the λ1 signal. Therefore, the output 6 of the amplifier 4 is only the λ2 signal, and the λ1
The outputs of the optical signal extraction circuits are 0. As a result, the λ2 signal is displayed on the monitor television 1o, and at the same time, the switching circuit 11 also outputs the λ2 signal, and the focus of the imaging lens 2 is automatically adjusted via the focus adjustment circuit 12 using the λ2 signal. Focus on the subject that is the source of the signal.

When a fire occurs, an optical signal with a wavelength λ1 corresponding to the fire is added to the incident light, and the output 6 of the amplifier 4 is the λ1 signal and λ1.
2 signals. This output 6 is applied to a λ1 optical image signal extraction circuit 5 and a λ2 optical image signal extraction circuit 9. λ
The optical image signal extraction circuit 5 extracts the λ1 signal corresponding to the fire, and applies it to the focus adjustment circuit 12 via the switching circuit 11. Therefore, the imaging lens 2 is focused on the fire source, which is the source of the λ1 signal, in response to the λ signal applied to the focus adjustment circuit 12. On the other hand, both the λ2 signal extracted by the λ2 optical signal extraction circuit 9 and the λ1 signal 7 from the λ1 optical image signal extraction circuit 6 are displayed on the monitor television 10. In this case, if input of the λ1 signal 7 to the monitor television 1o is made intermittent, the monitor television 10 can freely select and display only the λ2 signal and both the λ1 signal plus λ2.

According to such a configuration, monitoring is normally focused on the monitoring area (based on the λ2 signal), and when a fire occurs within that area, the fire source is automatically tracked to the fire source based on the λ1 signal caused by the fire. This makes it easier to monitor the situation at the fire scene by focusing on

In the above embodiments, a two-dimensional sensor is used, but the present invention can also be implemented using a one-dimensional sensor. Also, λ1. Although λ2 has been described in the infrared wavelength region, the focus may be adjusted by switching between light in the visible light region, for example, between a green light image and a red light image. Of course, a television camera is used as the imaging means in this case.

Furthermore, it may be switched between the wavelength λ1 in the visible light region and the wavelength 72 in the ultraviolet or infrared light region. These combinations may be used depending on the monitoring purpose.

Effects of the Invention As described above, the present invention obtains a plurality of different optical spectral band signals converted into electrical signals through an imaging lens, focuses the imaging lens on any of these signals, and then This imaging device is configured to switch the focus to the source of the signal when a specific signal is detected, and has the following effects.

(1) Since the object to be monitored is always in focus, it is possible to accurately capture the image.

(2) The positional relationship of monitored objects can be correctly deciphered.

(3) Measures taken against the monitored object, such as controlling the direction of a fire extinguishing nozzle toward the point of fire in the case of a fire, can be performed accurately.

(4) The surrounding situation can be monitored using conventional methods except when an abnormality occurs, and the switching circuit can be used to effectively monitor the situation only when an abnormality occurs.

[Brief explanation of the drawing]

FIG. 1 is an overall circuit block diagram of an imaging device according to the present invention;
FIG. 2 is a front view showing the configuration of a stripe filter used in the present invention, and FIG. 3 is a spectral characteristic diagram of the imaging device according to the present invention. 1...Incoming light, 2...Imaging lens, 3...
......-Sensor, 30...Incoming light encoding filter, 4...-Signal amplifier, 5...Output signal, 6......λ1 light beam Signal extraction circuit, 9...
. . . λ2 optical signal extraction circuit, 1o . . . Monitor television, 11 switching circuit, 12 . . . Focus adjustment circuit.

Claims (5)

[Claims] (1) an imaging lens, a sensor that converts an optical spectrum signal from a subject into an electrical signal, a monitor that displays at least a portion of the electrical signal, a means for extracting a specific signal from the electrical signal; An imaging device comprising: means for adjusting the focus of the imaging lens according to either the electric signal transmitted by the camera or the specific signal. (2) When a specific signal is obtained, the imaging lens is focused on the source of that signal.
The imaging device described in Section 1. (3) The imaging device according to claim 1, wherein the specific signal is an infrared signal. (4) The imaging device according to claim 1, wherein the sensor is an infrared two-dimensional sensor. (5) The imaging device according to claim 1, wherein the sensor is a visible light two-dimensional sensor.