TCRT5000

Vishay Semiconductors Application of Optical Reflex Sensors TCRT1000, TCRT5000, CNY70 Vishay Semiconductor optoelectronic sensors contain infrared-emitting diodes as a radiation source and phototransistors as detectors. Typical applications include: Copying machines Printers Object counters Video recorders Industrial control Proximity switch Vending machines Special features: Compact design Ambient light protected Operation range 0 to 20 mm Cut-off frequency up to 40 kHz High sensitivity High quality level, ISO 9000 Low dark current Automated high-volume production Minimized crosstalk These sensors present the quality of perfected products. The components are based on Vishay Semiconductors many years experience as one of Europes largest producers of optoelectronic components. Sensor Drawings 94 9442 94 9318 TCRT1000 TCRT5000 94 9320 CNY70 www.vishay.com Document Number 80107 1 02-02Vishay Semiconductors Optoelectronic Sensors In many applications, optoelectronic transmitters and There are no focusing elements in the sensors receivers are used in pairs and linked together described, though lenses are incorporated inside the optically. Manufacturers fabricate them in suitable TCRT5000 in both active parts (emitter and detector). forms. They are available for a wide range of The angular characteristics of both are divergent. This applications as ready-to-use components known as is necessary to realize a position-independent function couplers, transmissive sensors (or interrupters), for easy practical use with different reflecting objects. reflex couplers and reflex sensors. Increased In the case of TCRT5000, the concentration of the automation in industry in particular has heightened the beam pattern to an angle of 16 for the emitter and 30 demand for these components and stimulated the for the detector results in operation at an increased development of new types. range with optimized resolution. The emitting and General Principles acceptance angles in the other reflex sensors are about 45. This is an advantage in short distance The operating principles of reflex sensors are similar operation. to those of transmissive sensors. Basically, the light emitted by the transmitter is influenced by an object or The main difference between the sensor types is the a medium on its way to the detector. The change in the mechanical outline (as shown in the figures, see light signal caused by the interaction with the object previous page ), resulting in various electrical then produces a change in the electrical signal in the parameters and optical properties. A specialization for optoelectronic receiver. certain applications is necessary. Measurements and statements on the data of the reflex sensors are made The main difference between reflex couplers and relative to a reference surface with defined properties transmissive sensors is in the relative position of the and precisely known reflecting properties. This transmitter and detector with respect to each other. In reference medium is the diffusely reflecting Kodak the case of the transmissive sensor, the receiver is neutral card, also known as gray card (KODAK neutral opposite the transmitter in the same optical axis, giving test card KODAK publi-cation No. Q-13, a direct light coupling between the two. In the case of CAT 1527654). It is also used here as the reference the reflex sensor, the detector is positioned next to the medium for all details. The reflection factor of the white transmitter, avoiding a direct light coupling. side of the card is 90% and that of the gray side is 18%. The transmissive sensor is used in most applications for small distances and narrow objects. The reflex Table 1 shows the measured reflection of a number of sensor, however, is used for a wide range of distances materials which are important for the practical use of as well as for materials and objects of different shapes. sensors. The values of the collector current given are relative and correspond to the reflection of the various In the following chapters, we will deal with reflex surfaces with regard to the sensors receiver. They sensors placing particular emphasis on their were measured at a transmitter current of I = 20 mA F practical use. The components TCRT1000, and at a distance of the maximum light coupling. TCRT5000 and CNY70 are used as examples. These values apply to all reflex sensors. The However, references made to these components and black-on-white paper section stands out in table 1. their use apply to all sensors of a similar design. Although all surfaces appear black to the naked eye, The reflex sensors TCRT1000, TCRT5000 and the black surfaces emit quite different reflections at a CNY70 contain IR-emitting diodes as transmitters and wavelength of 950 nm. It is particularly important to phototransistors as receivers. The transmitters emit account for this fact when using reflex sensors. The radiation of a wavelength of 950 nm. The spectral reflection of the various body surfaces in the infrared sensitivity of the phototransistors are optimized at this range can deviate significantly from that in the visible wavelength. range. www.vishay.com Document Number 80107 2 02-02