CN2255817Y

CN2255817Y - Electronic testing instrument for visual acuity

Info

Publication number: CN2255817Y
Application number: CN 96227838
Authority: CN
Inventors: 张继开; 徐同一; 刘娟
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-05-14
Filing date: 1996-05-14
Publication date: 1997-06-11
Anticipated expiration: 2006-05-14

Abstract

The utility model relates to an electronic testing instrument for standard visual acuity, belonging to a medicine appliance, and comprising a test pattern display screen, a keyboard with a moving indication key or a visual acuity scale value key amd a control circuit connecting the test pattern display screen and the keyboard together. The control circuit is composed of a keyboard input circuit, a programmable controller and an output circuit which are connected in sequence. The pattern display program is loaded into the programmable controller by the utility model; a command is sent out through the key to make the test pattern display screen display standard test symbols with different sizes and directions. Thereby, the cheating behavior in the test procedure can be avoided.

Description

The electronic standard viseon tester

This utility model is a kind of electronic standard viseon tester, belongs to a kind of medical science apparatus.

Eyesight testing all uses the standard visual acuity chart of same arrangement mode at present, and promptly the direction of the letter of a certain position is certain, and this provides opportunity just for some man-hour, and they can recite visual acuity chart before test, thereby can obtain test result preferably.

The purpose of this utility model is: design a kind of electronic standard viseon tester that can show different sizes, direction standard test symbol according to indication at random.

This utility model comprises the test pattern display screen, has keyboard that moves indication button or vision scale value button and the control circuit that both are connected, and control circuit is made up of the keyboard input circuit, Programmable Logic Controller and the output circuit that connect successively.This utility model is packed the pattern displaying program in the Programmable Logic Controller, sends instruction by button, makes it show different sizes, the standard testing symbol of direction, can avoid the fraud behavior of doing in the test process thus.For ease of using, button inputting circuits can be connected by remote-control transmitting and receiving system thereof with Programmable Logic Controller.Also can directly install in this utility model and have vision scale value nixie display, its display circuit is connected with the outfan of Programmable Logic Controller and makes user of the present utility model can directly obtain test number.Also can insert printer, with its printing test result at the outfan of Programmable Logic Controller.In addition, the outfan of Programmable Logic Controller also can insert to wrong display or have microphone sound circuit reflection testee answer to wrong or directly broadcast test value by sound circuit.And above-mentioned Programmable Logic Controller is other known programmable control circuit, also can be a single-chip microcomputer, its ALE termination latch, and latch is connected with memorizer again; Said test pattern display screen, vision scale value the display drive circuit by separately and the outfan of single-chip microcomputer respectively join; Said sound circuit comprises the speech chip that is connected with the single-chip microcomputer outfan and the speech memory, the voice typing circuit that has microphone that join with speech chip respectively and voice amplification driving circuit and the loudspeaker that are connected successively at voice typing circuit output end; And keyboard-display circuit comprises keyboard display chip, led driver and the display that is connected with the single-chip microcomputer outfan, the input of led driver is connected with the outfan of a decoder and the outfan of keyboard display chip, the outfan of the input termination keyboard display chip of this decoder; In addition, printer, pattern displaying circuit, latch, keyboard display chip, the shared same signal transmssion line of memorizer and read/write address line, and WR line and RD line are by NAND gate map interlinking case display drive circuit.

Below in conjunction with accompanying drawing embodiment of the present utility model is elaborated.

Fig. 1 is the outline drawing of embodiment one;

Fig. 2 is the outline drawing of embodiment two;

Fig. 3 is the circuit block diagram of embodiment two;

Fig. 4 is the circuit diagram of embodiment two;

Wherein, 1-the five-grade marking system display, 2-are to wrong display, and the little numeral system of 3-shows not device, 4-loudspeaker, 5-pattern displaying screen, 6-shell, 7-keyboard.

As shown in the figure, embodiment of the present utility model comprises shell 6 and is installed in the control circuit that has each display in the shell 6 that each display then is installed on the shell 6.The core component of present embodiment is can be by instructing the electronic display circuit of display standard test symbol at random, the size of shown standard symbol, orientation are by a Single-chip Controlling, adopted 8031 chips in the present embodiment, its input is connected with the keyboard circuit that has button.For embodiment one keyboard circuit and single-chip microcomputer is directly to be connected by circuit, and its each button is installed on the shell.Then be connected with the input of single-chip microcomputer for embodiment two its keyboard circuits by the remote-control transmitting that matches and receiving circuit IC1, IC2 (chip SN76881 and SN76832).The ALE termination latch (chip 74LS373) of single-chip microcomputer, latch are connected with memorizer (chip 2716) again; Its outfan then connects keyboard-display circuit, sound circuit, scale value display circuit, pattern displaying circuit respectively, to wrong display circuit and printer, wherein keyboard-display circuit, latch, memorizer, the shared same holding wire of printer (P0.0-P0.7), and pattern displaying circuit, printer, shared its read/write address line of keyboard-display circuit (P3.6, P3.7), and this address wire is connected with the pattern displaying screen by NAND gate (chip CD4011).Wherein, first of single-chip microcomputer group of outfan (P1.0-P1.7) connects the scale value display circuit and to wrong display circuit.The scale value display circuit of present embodiment comprises the five-grade marking system display circuit and decimal system display circuit.The led drive circuit that display 1,3 in these circuit passes through separately respectively is connected with single-chip microcomputer, and these two led drive circuits have adopted chip IC 3, IC4 (MC14495).Wrong display 2 is then connect the outfan of single-chip microcomputer by a decoder IC5 (chip 74LS138).The LCDs drive circuit IC6 (SED1278) of second group of outfan (P2.3, P2.4) map interlinking case in succession display screen 5 of single-chip microcomputer.The 3rd group of outfan (P3.2, P3.4) connects sound circuit: it at first meets speech chip IC9 (UM5100), meet speech memory IC8 (SRAM6264) by speech chip again and have the voice typing circuit (chip LM324) of microphone, the outfan of voice typing circuit connects loudspeaker 4 by voice amplification driver IC7 (LM386).The 4th group of outfan (P2.6-P2.7) connects keyboard-display circuit: it at first connects keyboard display chip (chip 8279), meets decoder IC10 (74LS138) and led driver IC11, IC12 (BIC8708) by this chip again.Each outfan and the keyboard display of chip IC 12 connect power supply by resistance respectively.

Claims

1, a kind of electronic standard viseon tester, it is characterized in that: it comprises test pattern display screen (5), has the keyboard (7) of mobile indication button or vision scale value button, reaches the control circuit that both are connected, and control circuit is made up of the keyboard input circuit, Programmable Logic Controller and the output circuit that connect successively.

2, electronic standard viseon tester according to claim 1 is characterized in that: button inputting circuits is connected by remote-control transmitting and receiving system thereof with Programmable Logic Controller.

3, electronic standard viseon tester according to claim 1 and 2 is characterized in that: have a display circuit that has vision scale value nixie display to be connected with the outfan of Programmable Logic Controller.

4, electronic standard viseon tester according to claim 3 is characterized in that, has a printer to be connected to the outfan of Programmable Logic Controller.

5, electronic standard viseon tester according to claim 4 is characterized in that: have a pair of wrong display (2) or sound circuit to be connected to the outfan of Programmable Logic Controller.

6, electronic standard viseon tester according to claim 5 is characterized in that: said Programmable Logic Controller is a single-chip microcomputer, its ALE termination latch, and latch is connected with memorizer again; Said test pattern display screen (5), vision scale value the display drive circuit by separately and the outfan of single-chip microcomputer respectively join; Said sound circuit comprises the speech chip that is connected with the single-chip microcomputer outfan and the speech memory, the voice typing circuit that has microphone that join with speech chip respectively and voice amplification driving circuit and the loudspeaker (4) that are connected successively at voice typing circuit output end; And keyboard-display circuit comprises keyboard display chip, led driver and the display that is connected with the single-chip microcomputer outfan, the input of led driver is connected with the outfan of a decoder and the outfan of keyboard display chip, the outfan of the input termination keyboard display chip of this decoder; In addition, printer, pattern displaying circuit, latch, keyboard display chip, the shared same signal transmssion line of memorizer and read/write address line, and WR line and RD line are by NAND gate map interlinking case display drive circuit.