Infrared object detector

• US 5,637,040 A
• Filed: 04/10/1996
• Issued: 06/10/1997
• Est. Priority Date: 04/13/1995
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Tae-ho, Jung, Won-kyo, Lee, Sung-soo
• Primary Examiner(s): Joyce, Harold
• Application Number:
  US08/630,647
• Time in Patent Office: 426 Days
• Field of Search: 454/256, 454/313, 454/314, 454/315, 454/338, 340/567, 340/555, 250/221, 250/353, 250/342, 250/349, 165/16
• US Class Current: 454/256
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/64 using pre-stored data
• CPC Class Codes: F24F 11/77 by controlling the speed of ventilators
• CPC Class Codes: F24F 2120/10 Occupancy
• CPC Class Codes: G08B 13/19 using infrared-radiation detection systems G08B13/194 takes precedence

Abstract

An infrared object detector, especially for an air conditioner is provided with a light receiving unit including a light block between a pair of hemispherical Fresnel lenses arranged in parallel on a printed circuit board, so that light receiving views intersect each other to thereby define three detection areas. From a signal output from the light receiving unit, the distance to a detected object is determined through a signal processing circuit and a program built in a microcomputer. The rotational speed of a fan in the air conditioner is classified into three stages according to the determined distance, and a command is issued for controlling the operation of an air conditioner according to the number, movements, movement degrees to persons. Therefore, the airflow of the air conditioner is controlled based on the command, thereby performing an optimum air conditioning. Further, the infrared object detector can be applied to a camcorder or a camera, to determine the distance to an object more accurately.

Claims

1. An infrared object detector comprising:

light receiving means having at least one pair of light receiving lenses on a surface of a printed circuit board, light receiving views of said light receiving lenses intersecting each other to define a plurality of detection areas;

signal processing means having a light receiving element arranged on said printed circuit board, corresponding to each of said light receiving lenses, an amplifier electrically coupled to said light receiving element, a window comparator for comparing an output signal of said amplifier with a reference signal thereof, and a signal converter coupled to said amplifier in parallel with said window comparator for converting said output signal from said amplifier; and

determining means for determining the distance of a detection area where an object is located, through a signal output from said signal processing means.

2. An infrared object detector as claimed in claim 1, wherein said signal converter is an A/D converter.

3. An infrared object detector as claimed in claim 1, wherein said light receiving lenses are a pair of Fresnel lenses arranged in parallel, and light blocking means is provided between said Fresnel lenses so that the light receiving views of said Fresnel lenses intersect each other, thereby defining substantially three detection areas.

4. An infrared object detector as claimed in claim 3, wherein each of said pair of Fresnel lenses has a hemispherical light incident surface.

5. An infrared object detector as claimed in claim 3, wherein said light blocking means is a light blocking tape.

6. An infrared object detector as claimed in claim 3, wherein said light blocking means is a mask formed between said Fresnel lenses.

7. An infrared object detector for an air conditioner, comprising:

light receiving means having light blocking means between a pair of Fresnel lenses arranged on a surface of a printed circuit board, so that the light receiving views intersect each other to thereby define three detection areas;

signal processing means having a pair of light receiving elements disposed corresponding to said Fresnel lenses, an amplifier for amplifying an output signal of each of said light receiving elements, a window comparator for comparing an output signal of said amplifier with a reference signal, and an A/D converter coupled to said amplifier in parallel with said window comparator, for converting the output signal of said amplifier; and

a microcomputer for receiving a signal output from said signal processing means, determining a distance area where an object is located, and outputting a command signal for controlling the operation of an air conditioner according to the distance.

8. An infrared object detector for an air conditioner as claimed in claim 7, wherein each of said Fresnel lenses has a hemispherical light incident surface.

9. An infrared object detector for an air conditioner as claimed in claim 7, wherein said light blocking means is one of a light blocking tape and a mask.

10. An infrared object detector for an air conditioner as claimed in claim 7, wherein said signal processing means comprises an AND/NOT gate, for classifying signals output from two signal processing circuits thereof into said signal waves for signal detection areas, and determining a corresponding signal detection area.

11. An infrared object detector for an air conditioner as claimed in claim 7, wherein said microcomputer outputs a command signal for controlling the operation of said air conditioner according to the signal wave for the detection area output from said signal processing means.

12. An infrared object detector for an air conditioner as claimed in claim 7, wherein said microcomputer outputs a command signal for controlling the rotational speed of a fan in said air conditioner in three stages according to the signal wave for the detection area output from said signal processing means, thereby controlling the airflow of said air conditioner according to the number and movement degree of persons who are present in said detection area.