JPS5926138B2 - Dividing ratio setting device for programmable counter in synthesizer tuner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is used in a wideband scanning receiver (commonly referred to as a scanning receiver) using a PLL frequency synthesizer, in which an optical card is used to preset and store a desired reception channel. This invention relates to an optical card reader.

Preset multiple desired reception channels in advance,
The scanning receiver, which scans the preset channels and stops scanning when it reaches a channel where radio waves are being emitted and receives the radio waves from that channel, has been developed over the conventional quartz crystal due to the spread of PLL systems with the development of engineering technology. The oscillator control method has been replaced by the PLL frequency synthesizer control method. In this case, a device is required to preset and store desired channels. This storage device includes a switch memory type, a semiconductor memory type, and a card memory type, but the card memory type is the simplest in terms of product price and ease of operation. This is because if data is written by punching a hole in a non-perforated card or closing the hole in a perforated card, many channels can be easily preset simply by replacing the card. The PLL frequency synthesizer includes a programmable counter from which the frequency division ratio is determined by extracting the presence or absence of a hole in the card of the storage device as a binary code, a reference oscillator, and a reference signal from this oscillator and a signal from the programmable counter. a phase detector that detects the phase difference with the output signal and converts it into a change in voltage; a low-pass filter that integrates and smoothes the output voltage of the phase detector; and a low-pass filter that receives the output from the filter as a control voltage. Therefore, it consists of a voltage controlled oscillator whose oscillation frequency is controlled, and the output of the voltage controlled oscillator is used as the local oscillation frequency of a radio receiver, for example.

The present invention relates to an improvement of the above storage device, that is, an optical card reader. Conventionally, for a card having a memory section of mXn (where m and n are integers of 1 or more), for example, 16 channels x 16 bits, This required 256 light emitting elements and 256 light receiving elements, making it an extremely expensive device. Furthermore, if each channel's 16-bit irradiation band is irradiated by one light emitting element, the number of light emitting elements can be reduced, but in that case, the light emitting element is required to be of high brightness such as a tungsten lamp, which reduces the lifespan and heat generation. There were problems with this. An object of the present invention is to improve the reliability and lifespan of an optical card reader and to provide an inexpensive device.

In order to achieve the above object of the present invention, improvements have been made to the light emitting element before the card and to the light emitting element after the card.

First, on the light emitting element side, in order to make one light source equivalent to m light sources, a reflector is used that has one incident surface and m reflecting surfaces corresponding to bit numbers l-m. using 1
The incident light from one incident surface is divided into m reflected lights that are almost parallel to each other.

A desired number of such reflectors for n channels are prepared and arranged in a line. On the light-receiving element side, when using CdS as the light-receiving element, instead of providing a single CdS element for each bit of n><m memory planes, m strips of CdS are used.
Elements are prepared and arranged so as to be perpendicular to each of the reflectors, so that one element receives the reflected light from the reflecting surface of the same numbered bit of each channel. This allows CdS
The number of is reduced to m. By doing this, the number of light emitting elements for each channel is sufficient, and since the light emitted from the light source is reliably guided by the reflector, the brightness of the light emitting elements does not need to be as high as before. , low-brightness LEDs, etc. can be used, which has great effects in terms of lifespan and cost.

Further, in the light receiving element, the conventional NXm CdS is reduced to m. Embodiments of the present invention will be explained below based on the drawings.

FIG. 1 is a block diagram showing an embodiment of the scanning receiver of the present invention. This scanning receiver is roughly divided into three blocks: a receiver section 10, a PLL frequency synthesizer section 20, and a division ratio setting section 30 for the programmable counter 25. As is well known, the receiver section 10 includes an antenna 1, a high frequency amplifier 2, and a first intermediate frequency stage 3 including a mixer.
, a second intermediate frequency stage 4 , a low frequency amplifier 5 and a speaker 6 . In the PLL frequency synthesizer section 20, 21 is a reference oscillator, and 22 is a phase detector that detects the phase difference between the reference signal from the oscillator 21 and the output signal from the programmable counter 25, and converts it into a change in voltage. 23 integrates and smoothes the output voltage of the phase detector 22;
This is a low-pass filter that supplies DC voltage to the voltage controlled oscillator 24.

The voltage controlled oscillator 24 is an oscillator whose oscillation frequency is controlled by the applied control voltage, and this output frequency F
. is used as a local oscillation frequency of the receiver section 10, for example. The programmable counter 25 is a counter whose frequency division ratio (N value) can be set to any integer, and the N value is determined by the binary code input to its multiple input terminals 251, 252, ... 25m). Set. Here, phase detector 22 - low pass filter 23 - voltage controlled oscillator 24 -
In a closed loop with programmable counter 25, P
It is well known that when LL is phase-locked, FO=Fi-N. However, f1 is the reference oscillation frequency. The division ratio setting section 30 is the programmable counter 25.
It is mainly divided into a scan control circuit 31 that controls the scanning of the light emitting element 33, an optical card reader section 32, and a switching circuit group 37.
The optical card reader section 32 includes a light emitting element group 33, a reflector group 34, a card 35, and a light receiving element group 36, and the present invention is included in this card reader section 32.
The card reader section 32 will be explained using figures.

FIG. 2 shows an exploded perspective view of one embodiment of the card reader section 32 and a circuit diagram of one embodiment of the switching circuit group 37. The light emitting elements 331 and 33 are prepared in n number of channels and are sequentially and repeatedly turned on by the scan control circuit 31.

34,,342,...34.

are reflectors made of a transparent material such as acrylic resin, and are arranged parallel to each other in correspondence with each light emitting element. Each reflector, for example, the reflector 341 has a light emitting element 331a,
331b, . . . are attached to the incident surfaces 341a, 341b, and m step-shaped reflective surfaces 34.
1-,,341-2...34,-. It divides the incident light from the incident surfaces 34, a, 34, b into m substantially parallel reflected lights. Here, the light emitting element 331a,
331b is embedded in both sides of the reflector 341,
This may simply be placed opposite to both side surfaces of the reflector 341. 41 is the reflector 341, 342...
The board is provided with m band-shaped light receiving elements (for example, CdS) 361, 362, . The electrode 42 connected to the power terminal C
An electrode 43 connected to c is provided, forming a striped pattern.

The switching circuit group 37 includes m switching circuits 37.
1,372,...37[Tl]. Each switching circuit consists of two transistors 4, for example.
The base of the transistor 44 is connected to the electrode 42, and the collector of the transistor 45 is connected to the input terminal of the programmable counter 25 via a resistor. To describe an example of the operation from the light emitting element group 33 to the switching circuit group 37, for example, the light emitting element 33,a lights up, the light enters the reflector 341 from the incident surface 34,a, and is reflected by the reflective surfaces 341-, When reflected, the light decreases the resistance value of the light receiving element 361 (CdS) and changes the transistor 441 to the 0N1 transistor 45.
The switching circuit 371 is controlled so that 1 is set to 0FF, and the input terminal 251 of the programmable counter 25 is set to 0.
” is input in binary code.Here, each light receiving element 431~
43 [n denotes reflectors 341 to 34 provided corresponding to each vertical column of cards to be described later. are provided corresponding to each horizontal row of cards. Reference numeral 35 is a card that can be punched with m columns of holes and n columns of holes.
A binary code of "0" or "11" is input to each of the input terminals 251, 252, .

Therefore, by sequentially blinking the light emitting elements 331, 332, .
By controlling the operation of the programmable counter 25 and determining the division ratio of the programmable counter 25, the local oscillation frequency of the scanning receiver can be controlled. FIG. 3 shows an enlarged side view of the reflector 34 when m is 16.
, -8, the incident light from the incident surface 341b is directed to the reflective surface 3
It is divided into 16 parallel light beams by 4, -,,34,-10...341-16.

Note that the angle θ of each reflecting surface is determined by design based on the position of the incident surface, the length and height of the reflector, and the like. In addition, when acrylic resin is used as a reflector and an LED is used as a light emitting element, the critical angle 1c for total reflection on the internal surface of the acrylic resin is the refractive index n of the acrylic resin (n = 1.49, but the red light of the LED can be derived from the wavelength λ-6600A). Among the reflecting surfaces, those whose angle θ exceeds the critical angle may be coated with aluminum vapor deposition or the like to cause total reflection.

Further, in the above embodiment, the reflecting surface of the reflector 34 is configured to be V-shaped, but it may be tapered, for example, from the upper left to the lower right. In this case, the light emitting element is arranged only on one side of the reflector 34. As can be seen from the above, according to the present invention, the above-mentioned conventional drawbacks can be solved, the reliability and life of the optical card reader can be improved, and an inexpensive optical card reader can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the scanning receiver of the present invention, FIG. 2 is an exploded perspective view of the card reader section of FIG. 1 and a circuit diagram of an embodiment of the switching circuit, and FIG. FIG. 3 is an enlarged side view of the reflector shown in FIG. 32... Optical card reader section, 33...
...Light emitting element, 34...Reflector, 35...
... Card, 37 ... Switching circuit group, 4
1... Light receiving element board.

Claims (1)

[Claims] 1 comprising n light emitting elements that are sequentially turned on in a fixed scanning time by a scan control circuit, at least one incident surface and m reflective surfaces corresponding to each of the light emitting elements, and each of the light emitting n reflectors that receive emitted light from the element from the incident surface and divide it into m mutually substantially parallel reflected lights by the reflective surface, and are freely insertable and removable from the n reflectors; a card having holes that are programmable to transmit or block n×m reflected lights from the reflector; and a reflective surface of the same order of each reflector that is perpendicular to the reflector and that can pass through the card. m light-receiving element groups that commonly receive reflected light from each other, and m switching circuits configured to output binary codes by the operation of each of the light-receiving elements; An optical card reader for setting a frequency division ratio of a programmable counter in a synthesizer tuner, characterized in that the frequency division ratio of the programmable counter is determined by inputting .