CA1338573C - Liquid-crystal display unit for electronic directory - Google Patents

Abstract

A liquid-crystal display, preferably twenty-five lines of eighty characters each, is mounted in a case. The temp-erature of the display medium is maintained within operat-ing limits for the display -- notwithstanding ambient tem-perature and humidity variations over generally normal ranges for at least the temperate zones, and even if the display unit is placed to receive direct sunlight. The unit works outdoors as well as in buildings that lack tem-perature control. This is accomplished preferably by cir-culating air from outside the case through a space between the display face and an unperforated protective polycarbo-nate window. Intake and exhaust plena are long and narrow enough to deter manual access to the display and thus van dalism; however, the plena are straight and sufficiently free of obstructions that the fan can be a very small, low-power, quiet unit. A temperature sensor controls the fan, and also the contrast-adjusting voltage of the display -- based on data in a digital-memory "look up" table. A
heater is preferably provided, also temperature-controlled.
The plena face downward so that the unit is not sensitive to rain, and the entire unit can be flush-mounted in a wall without disrupting system cooling. Visible glare arising in reflection at the window is reduced by an antireflection coating on the window.

Description

1 338~3 74613-9D
BACKGROUND
1. FIELD OF THE INVENTION
This application is a division of our Canadian patent application Ser. No. 604,165 filed June 28, 1989.
This invention relates generally to practical display units for electronic directories and like electronic tabulations for public viewing; and more particularly to a display unit for an electronically controlled directory that employs a liquid-crystal display. It also relates to a telephone entry system.

2. PRIOR ART
Directories are commonly posted in the public lobbies of business buildings, apartment houses, multiple-building condominium complexes, and other multiple-occupant facilities. In secured facilities, the entries in such directories often include room or suite numbers, or other numbers for use with an adjacent telephone or intercom in contacting individual occupants to gain admission.
In a few large facilities, recently, hand-lettered or movable-letter directories have given way to electronic systems that are much easier to revise. Such systems eliminate tedious manual reshuffling of placards or letters to keep entries in alphabetical order and to accommodate subdivision or consolidation of occupant suites.
Although they are an enormous improvement over manual directories, the electronic systems have suffered from a ' I!

1 major limitation in their use of cathode-ray-tube (CRT) 2 display units. Such video display units, in the forms 3 currently encountered in commercial practice, have several 4 well-known drawbacks.
The drawbacks of CRT displays include image 6 instability, poor resolution and (particularly in bright 7 light) poor contrast. Instability of the image, ranging 8 from minor flicker to vertical roll, can make reading the 9 information on the screen difficult.
Poor resolution severely limits the number of entriés 11 that can be displayed simultaneously on a screen of 12 moderate size. This strategy sometimes leads to very large 13 screens that visually dominate a lobby.
14 Some system designers attempt to avoid this drawback by programming the units in operating modes that call upon 16 a visitor to "page through" different screens to find a 17 particular occupant. The "page through" mode itself is in 18 principle entirely acceptable, but when the number of 19 entries on a screen is unduly small -- so that a typical visitor must search through several screens even for a 21 relatively small directory -- the typical visitor 22 justifiably becomes annoyed. That is what happens with a 23 CRT display, because of its limitations.
24 Alternative methods for locating an occupant without paging are either more complicated or more expensive, or 26 both. For example, some systems provide a large 27 alphanumeric keypad and require the user to spell the first 28 few letters of the occupant's name. This increases the l l 1 system cost and also reduces convenience, particularly for 2 a user who is unsure how to spell the name.
3 In general all these drawbacks also detract from 4 efforts by facility management to establish an elegant or prestigious style in a lobby or outdoor entry area. Poor 6 contrast is considered among the worst offenders in this 7 regard.
8 Sometimes, in the interest of offsetting poor 9 contrast, directory system designers introduce the use of colors in the video display. Often, however, this strategy 11 is counterproductive, because the CRT or video colors 12 inject an incongruously gaudy element into a fine decor.
13 CRT displays are particularly t~oublesome in brightly 14 lit environments such as outdoors and in lobbies surrounded by large windows that admit brilliant sunlight. In these 16 circumstances, contrast can be so inadequate that the 17 displays are almost completely unreadable.
18 Moreover, CRT displays are relatively expensive. In 19 large formats they are too deep (front to back) for straightforward mounting in a wall -- and so require 21 provision of a free-standing or recessed support structure 22 enclosure two or three feet deep. Because of their 23 evacuated-chamber construction, they are also relatively 24 fragile and inordinately subject to vandalism.
Other types of display are known for use with 26 electronic information processors, but heretofore not with 27 electronic directories or other large electronic 28 tabulations for public viewing. Such other types include .
1 the light-emitting diode (LED) and the liquid-crystal 2 display (LCD).
3 Most LEDs require relatively bulky apparatus for each 4 character to be displayed. Furthermore LEDs are quite dim, and in the few very-small-screen outdoor applications where 6 they have been used (such as some automatic-teller 7 machines) they are extremely hard to read -- even when 8 elaborately shaded. A larger LED array such as required 9 for a directory would be prohibitively difficult to shade effectively and would be inordinately expensive.
11 Under ideal conditions, liquid-crystal displays are 12 capable of excellent contrast and resolution, are plainly 13 readable even in the brightest light, and are readily 14 backlighted for nighttime use. Their use would also result in a far less expensive and much more compact product 16 package. LCDs would accordingly be excellent candidates 17 for directories and the like, but we are not aware of any 18 prior suggestion for such use; and they do have important 19 limitations.
An LCD has a display medium -- the liquid-crystal 21 fluid itself -- and a structure which contains the fluid.
22 In at least some commercial LCDs this structure typically 23 includes two planar pieces of material with the medium 24 sandwiched between them. At least the piece on the viewing side of the sandwich, which in this document we will call 26 the LCD "face," ordinarily is transparent glass or plastic.
27 Electrodes are formed on the opposed interior surfaces 28 of this sandwich. These electrodes too are ordinarily t transparent on at least the face side. One electrode 2 material is intrinsic tin oxide.
3 Both the fluid and the glass are very sensitive to 4 temperature. (It may be recalled that the early applications of liquid-crystal displays were as novelty 6 items, particularly including thermometers.) 7 If the temperature of the glass rises beyond certain 8 relatively narrow limits, the display develops dark spots, 9 or the entire display may actually turn dark. As we understand it, this darkening is due to an expansion of the 11 cell gap within the glass. The black characters or other 12 symbols then fail to stand out well against the darkening 13 background.
14 On the other hand, if the temperature falls too much, the changing of characters begins to be very slow, an 16 effect which is said to be related to increasing viscosity 17 of the medium. As temperature decreases further the 18 display blushes a different color (e. g., pink) -- this 19 time because of the cell gap's contraction -- and again becomes unreadable.
21 Directory applications would call for use of the 22 larger graphic LCDs, and also for a type of medium known as 23 "supertwist" fluid. This kind of fluid provides far 24 superior contrast and hence significantly better readability. The large LCDs, however, and especially those 26 using supertwist fluid, are particularly sensitive to 27 temperature.
28 Presumably for these reasons LCDs heretofore have ~I i 1 been used primarily in applications involving small formats 2 or intrinsic temperature control, or both. Thus LCDs are 3 employed extensively for wristwatches -- since they can 4 make good use of LCDs that are smaller and nonsupertwist, and therefore less temperature-sensitive. LCD wristwatches 6 also take advantage of the wearer's limited temperature 7 tolerance, and heat conduction to and from the wearer's 8 body, to limit the severity of temperatures to which the 9 display is exposed.
Even under such relatively protected conditions, 11 fading and blushing or wristwatch displays is well known to 12 athletes and workers whose activities reach the anticipated 13 design limits of the watches.
14 LCDs are also used for many usually indoor applications such as calculators and laptop computers.
16 Here too they are typically used in temperature-controlled 17 environments, or if they are found to malfunction can 18 generally be moved into such environments.
19 Operation of large LCDs would be subject to temperature problems in lobbies and other indoor entryways, 21 as well as outdoors, if the locations receive intense 22 sunlight. Temperature rise in such areas sometimes 23 outstrips the capabilities of a building air-conditioning 24 system, and can be severe enough to degrade the performance Of an LCD.
26 If the LCD were inside a case, and were protected from 27 vandals by an unbreakable window, as is desirable in our 28 application, the temperature problem would be aggravated 1 much ,further. This would be due to a "greenhouse" effect, 2 in which stagnant air between the window and the LCD
3 becomes extremely hot, much like the interior of a car left 4 shut on a hot day.
A related problem of LCD temperature sensitivity 6 involves a voltage that is applied to the display medium to 7 control the contrast of the characters relative to the 8 background screen. The necessary voltage for proper 9 contrast varies very strongly and nonlinearly with temperature.
11 Thus, as the temperature to which the LCD is exposed 12 changes (e. g., between day and night), the LCD contrast 13 would have to be constantly adjusted to prevent its 14 characters from disappearing or becoming illegible. A very nonlinear relationship between the voltage and the 16 temperature renders the problem of automatic 17 contrast-control technique far from straightforward.
18 For whatever reason, LCDs have not been used in 19 sizable directory-type displays. We will return to more general discussion of electronic directories and the like.
21 Another problem arises in configuration of such 22 directories and the like, when outdoor or bright-lobby 23 applications are involved. That is the problem of 24 controlling reflections at glass or plastic surfaces of the display unit.
26 Such reflections of the viewing person -- and of 27 objects around and behind that person, become confused with 28 the displayed characters, making them very hard to read.

1 When sufficiently bright, these reflections actually 2 obscure the displayed characters.
3 As a verbal shorthand we shall refer to these 4 confusing and obscuring reflections collectively as "glare." Such glare can be controlled to a certain extent 6 by providing a matte finish on the screen itself, provided 7 that the electronic display screen (such as a CRT screen) 8 is directly exposed to the viewing person. Direct exposure 9 of the display screen is accordingly a conventional teaching of the prior art.
11 This conventional teaching, however, severely limits 12 the use of electronic directories since it makes them 13 susceptible to vandalism. Direct exposure of the display 14 screen makes it easy for a vandal to break the screen or damage the display unit.
16 Hence there is a conflict between the direct exposure 17 desired to control glare, and the interposition of an 18 intermediate protective window desired to control vandals.
19 This conflict is present with CRTs and LEDs -- but particularly acute with LCDs because of the very way they 21 work.
22 CRTs and LEDs inherently generate their own 23 illumination, but LCDs usually depend upon incident light 24 for their characters to be seen. Different portions of the fluid will either absorb or reflect incident light, and 26 thus form visible characters, depending on whether or not 27 the fluid is electrically excited.
28 This mechanism explains why LCD characters do not 1 338~73 1 seem to fade in direct sunlight as do CRT and LED
2 characters. Light that is reflected at a glass or plastic 3 surface, however, is light not used to develop visible LCD
4 characters -- and, in fact, is light that creates reflections which compete with the already diminished LCD
6 characters.
7 Thus, again, even if there had been a suggestion of 8 LCD use in electronic directories, such a suggestion would 9 have been particularly likely to meet with immediate rejection in view of the relatively adverse glare-related 11 properties of LCDs.
12 Finally, even though the electronic directory systems 13 currently available are far more convenient in terms of 14 entering and deleting names than the movable-letter or placard directories, they still require local procedures 16 for entries or revisions -- either at the system itself or 17 through a computer close by. This arrangement is very 18 inconvenient for buildings that have off-site property 19 management, especially when tenant turnover is high and frequent directory changes required.
21 All of the above limitations have resulted in the 22 relatively limited use of currently available electronic 23 directories. As can now be seen, the prior art has failed 24 to provide an adequate display system for directories and the like, particularly for use out of doors and in lobbies 26 or other entryways subject to intense sunlight.

SUMMARY OF THE DISCLOSURE
This invention relates to a telephone-entry system and to a display unit for an electronic directory. The display unit includes a case, and it also includes a liquid-crystal display (LCD) that is mounted within the case.
Like all liquid-crystal displays, the LCD that is part of our display unit has a display fluid, liquid or the like which we will call the "display medium"; and a structure (described in an earlier section of this document) that contains the fluid. As is well known, the operating temperature of the display medium and structure -- and therefore of the display in general -- has a distinctly limited range. Even within this limited range, performance varies strongly with temperature.
Our display unit also includes some means for maintaining the temperature of the liquid-crystal display medium and structure between practical operating limits for the display.
For generality of expression in describing our invention, we shall refer to these means as the "temperature-maintaining means."
These temperature-maintaining means are at least partially mounted within the case. They maintain the display-medium and display-structure temperature within its operating range notwithstanding ambient temperature and humidity variations over generally normal ranges for at least the temperate zones.
Furthermore the temperature-maintaining means 1 maintain the temperature within practical limits even if 2 the display unit is placed to receive direct sunlight when 3 the sun is out.
4 The foregoing may be a definition of our invention in its broadest or most general terms. For maximum enjoyment 6 of the benefits of our invention, however, we prefer to 7 incorporate certain additional features or characteristics 8 into devices made in accordance with the invention.
9 For example, we prefer that the temperature-maintaining means hold the temperature of the medium and 11 structure at least between positive 160 degrees and 12 negative 35 degrees Fahrenheit. We consider these limits 13 adequate to provide reasonably good,-reliable performance.
14 To provide even better and more reliable performance, however, we prefer that the temperature-maintaining means 16 hold the temperature of the medium and structure between 17 even tighter limits. It will be understood that there is a 18 continuum of improving performance and reliability with 19 progressively narrower operating limits, so that no absolute values can be stated; but through much careful 21 trial and error it is possible to select temperature limits 22 that are cost effective.
23 Accordingly we prefer that the temperature-maintaining 24 means hold the temperature of the medium at least between positive 120 degrees and negative 15 degrees Fahrenheit.
26 We prefer that the temperature-maintaining means do so in 27 direct sunlight with ambient temperature between 115 and 28 -40 degrees Fahrenheit.

1 3~7~
1 In a preferred form of our invention, the 2 temperature-maintaining means include an external viewing 3 window mounted to the case and generally spaced away from 4 the LCD face, along the viewing direction. The viewing window thus defines an air-circulation region immediately 6 adjacent to the face. This window is preferably breakage 7 resistant and so provides an additional important 8 function: resistance to vandalism.
9 This preferred embodiment also has some means for defining intake and exhaust plena. Again for purposes of 11 generality in expression, we will call these means the 12 "plenum-defining means."
13 The plenum-defining means define an intake plenum 14 leading from the outside of the case to the air-circulation region, and a separate exhaust plenum leading from the 16 air-circulation region to the outside of the case. Each 17 plenum is long and narrow enough to substantially deter 18 manual access to the liquid-crystal display through the 19 plena.
The preferred embodiment under discussion also has at 21 least one fan disposed to circulate air from the intake 22 plenum through the air-circulation region to the exhaust 23 plenum. The intake and exhaust plenum terminations at the 24 outside of the case face downward, and preferably are in the bottom of the case itself.
26 In principle the viewing port can simply be left open 27 -- that is, with no viewing window at all -- to optimize 28 the air circulation for temperature control.

1 Alternatively the viewing window can be perforated, to 2 provide some air circulation through the window port as 3 well as behind it. Omitting the viewing window also has 4 the advantage that there is no glare-producing reflective surface spaced forward from the LCD.
6 Such systems are in fact within the scope of our 7 invention as most broadly defined above. They may be 8 preferable in some types of installations, particularly 9 where the risk of vandalism is minimal. That is so, for example, where the display unit is only exposed to 11 employees of the facility or to other prequalified 12 personnel.
13 For more general applications, however, even at the 14 cost of some benefit in temperature and glare control, we prefer to enhance security by including a viewing window 16 that is free of perforations. We have found that even with 17 such a window it is possible to achieve completely adequate 18 temperature control with very low cost, low power 19 consumption and low fan noise.
In particular we achieve these advantages by using a 21 fan that is free of air-flow obstructions such as guard 22 meshes or louvres, and by making each plenum at least very 23 generally straight and substantially free of air-flow 24 resistance elements such as guard meshes, louvres, or abrupt surface discontinuities of the plenum itself.
26 This geometry makes it possible to achieve the needed 27 air circulation using only a very quiet, low-power fan.
28 For best temperature control, we prefer to provide two 1 338~73 -1 such fans, one associated respectively with each plenum.
2 We dispose each fan substantially adjacent to the LCD
3 face, substantially out of sight of viewers examining the 4 LCD medium through the viewing window along typical viewing directions. It will be understood that the fan or fans 6 need not be operated at all times, but only when ambient 7 temperature and incident sunlight cause the temperature to 8 drift outside acceptable operating limits.
9 We prefer to include a temperature sensor for monitoring the temperature of the LCD medium. We also 11 prefer to include some means for controlling the fan in 12 response to the sensor. Again for generality, we shall 13 call these the "fan-controlling means."
14 We prefer to use the same sensor to adjust the LCD
contrast-control voltage too. The sensor controls that 16 voltage through a voltage-adjusting circuit that includes 17 an analog-to-digital ("A/D") temperature-conversion stage 18 and a digital electronic memory. This memory holds a 19 lookup table for establishing desirable contrast-control voltage values for various temperatures.
21 After some experimentation we have come to prefer this 22 system because the voltage requirement varies strongly with 23 temperature, particularly toward the extremes of the 24 temperature operating range, and is difficult to represent in closed form as by a formula. We prefer to include A/D
26 conversion of temperature because representing the 27 voltage-temperature relationship with an analog circuit is 28 relatively difficult and expensive.

1 Because that relationship is difficult to represent in 2 closed form as by a formula, we prefer to use a look-up 3 table. This approach has the added benefit of allowing us 4 to easily change the relationship to account for differences in display lots or even different displays we 6 might subsequently use.
7 We also prefer to provide a heater for raising the LCD
8 temperature, and to provide "heater-controlling means" for 9 operating the heater only when needed. The heater-controlling means are also responsive to 11 temperature.
12 As previously mentioned, visible glare can arise in 13 reflection at the solid viewing window. Nonreflecting 14 glass such as is used with picture frames fails to cure such glare, as the nonreflecting characteristic is attained 16 by using a matte finish; and only images immediately behind 17 the glass are clearly visible through such a finish.
18 It may be emphasized that the LCD face itself 19 typically carries such a matte finish, which does in fact minimize glare arising at the LCD face. The glare now 21 under discussion, however, arises not at the LCD face but 22 at the forward viewing window.
23 We have found that such glare can be effectively 24 controlled by vacuum-depositing an antireflection coating of the type used for eyeglasses. Resort to this solution 26 is far from obvious, since the equipment used for coating 27 eyewear is particularly configured for that purpose --28 particularly for simultaneous coating of a large number 1 of small lenses, not our much larger viewing windows.
2 Once it is called for, however, the modification of 3 such equipment for coating viewing windows of the type 4 under discussion here is straightforward, for a person skilled in the art of mechanical devices.
6 The viewing window is preferably of unbreakable 7 plastic such as polycarbonate. The best materials for use 8 in forming a graded-index antireflection coating for the 9 window accordingly may differ from those used for eyeglasses.
11 In particular, we prefer to make the viewing window of 12 the plastic available commercially under the trade p~m~
13 "Lexan." After some experimentation-it has been found that 14 the antireflection coating may include three layers of material on both sides of the Lexan window, each layer 16 being a different material. In the alternative, with 17 better performance, five layers may be used on both sides 18 of the window.
19 The formulation for the three-layer and five-layer alternatives can be those commercially available from 21 Pacific Universal Corporation in Pasadena, California, 22 under the names "AR-narrow band" and "AR-broad band"
23 formulations, respectively, for polycarbonate. These names 24 would also identify similar composite coatings of other suppliers.
26 As mentioned earlier, prior to our invention, all 27 electronic directories required local programming, either 28 at the unit or through a computer close by, via a hardware connection. Our electronic directory system can instead be programmed remotely from any location via telephone line, using either a modem and terminal or a tone-transmitting telephone by itself. In the latter case, our electronic directory system provides synthesized voice responses to supply status and progress information to the programmer over the telephone.
Our system can also be programmed locally, using a very inexpensive handheld membrane-type alphanumeric keypad that plugs into the system electronics directly. Alternatively, the system can also be programmed using a twelve-button keypad on the front panel of the system.
According to a broad aspect of the invention there is provided a telephone-entry system for use by a visitor to a facility having multiple individual-occupant entities, and having telephone service, and having individual telephone outlets at the individual-occupant entities respectively; said system comprising:
a microphone and audio speaker, disposed for use by such visitor when seeking access, for voice communication between such visitor and an occupant of such individual-occupant entity; electrical communication-circuit means, interconnected with the microphone and audio speaker, for effectuating said voice communication through one of such individual telephone outlets by carrying electrical signals between (1) the microphone and speaker and (2) such telephone service; manually operable controls, disposed for use by such visitor; electronic memory means for holding directory information for such facility, particularly including names of such individual-occupant entities;a liquid-crystal display, disposed for viewing by such visitor, and having a display medium and a structure for containing the display medium; said liquid-crystal display structure comprising a face, disposed in front of the medium, for displaying the directory information; and at least one digital electronic microprocessor, electrically interconnected with and responsive to the manually operable controls, and electrically interconnected with the electrical communication-circuit means, the memory means and the liquid-crystal display, for: reading the directory information from the memory means, controlling the liquid-crystal display to exhibit the directory information; controlling the sequence of directory-information exhibition by the liquid-crystal display, and controlling the electronic communication-circuit means to initiate communication, via such telephone service, with a particular individual-occupant entity selected by such visitor from the directory information displayed by the liquid-crystal display.
According to another broad aspect of the invention there is provided a telephone-entry system for use by a visitor to a facility having multiple individual-occupant entities, and having telephone-system service, and having individual telephone outlets at the individual-occupant entities respectively; said system comprising: a microphone and audio speaker, disposed for use by such visitor when seeking access, for voice communication between such visitor and an occupant of such individual-occupant entity;
electrical communication-circuit means, interconnected with the microphone and audio speaker, for effectuating said voice communication through one of such individual telephone outlets by 18a carrying electrical signals between (1) the microphone and speaker and (2) such telephone service; manually operable controls, disposed for use by such visitor; electronic memory means for holding directory information for such facility, particularly including names of such individual-occupant entities; a display, disposed for viewing by such visitor, for displaying the directory information; at least one digital electronic microprocessor, electrically interconnected with and responsive to the manually operable controls, and electrically interconnected with the electrical communication-circuit means, the memory means and the display, for: reading the directory information from the memory means, controlling the display to exhibit the directory information, controlling the sequence of directory-information exhibition by the display, and controlling the electronic communication-circuit means to initiate communication, via such telephone service, with a particular individual-occupant entity selected by such visitor from the directory information displayed by the display; and means for programming, remotely from the control means and at least one microprocessor, the directory information held in the electronic memory means.
All of the foregoing operational principles and advantages of the present invention will be more fully appreciated upon consideration of the following detailed description, with reference to the appended drawings, of which:
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is an exterior perspective drawing, taken from slightly above and to one side, of a display unit that is a 18b 1 ~3~5~

preferred embodiment of our invention.
Figure 2 is an interior perspective view, taken from below and drawn partially broken away, of the Figure 1 embodiment with its front panel opened to show the interior construction and arrangement.

18c -1 Fig. 3 is a side elevation, partly in cross-section 2 and enlarged, showing the relationships of the viewing 3 window, the LCD face, and the temperature sensor.
4 Fig. 4 is a block diagram of the programming processing flow for the system and shows the different 6 programming devices that can be used along with the major 7 electronic components used to process their input.
8 Fig. 5 is a picture of our handheld programmer -- one 9 of the devices used to program the system at the system.

14 As seen in Figs. 1 and 2, the preferred embodiment of our display unit has a case 101 that includes a front panel 16 107. The case 101 also includes a rear wall 103, left and 17 right side pillars 104, 105, a ceiling 106, a floor 107, 18 and a rain gutter 201 (Fig. 2). We prefer to make the 19 front panel stainless steel and the case painted cold-rolled steel.
21 The front panel 102 is hinged to the right pillar 105, 22 and provided with a keyed lock 107 that engages a strike 23 groove 202 (Fig. 2) formed in the left pillar 104 to secure 24 the front panel firmly against the rear parts 103-106 of 2~ the case. Formed in the front panel 102 are a viewing port 26 111, louvres 112 and an array of twelve small square access 27 holes 113, a small hole 114 and a larger hole 115.
28 The louvres 112 are provided for transmission of 1 338~

1 sound from an audio speaker 203 (Fig. 2) that is mounted 2 behind the front panel 102. The square access holes 113 3 accommodate twelve pushbuttons of a standard telephone-type 4 pushbutton array 116. The small hole 114 allows for transmission of sound to a microphone 204 (Fig. 2) that is 6 mounted directly behind the hole. The larger hole 115 is 7 for installation of a post-office key lock. If this lock 8 is not used, a plug fills the hole.
9 Securely mounted to the rear surface of the front panel 102, behind the viewing port 111, is a polycarbonate 11 viewing window 117, which carries an antireflection 12 coating. Behind the window is an LCD 120, preferably eight 13 to twenty-five rows of twenty to eighty characters each.
14 As previously explained, the antireflection coating on the window 117 reduces "glare" (as defined above) 16 sufficiently that the LCD 120 can be read. This function 17 is particularly important when the LCD is facing away from 18 the incident sunlight.
19 When that is so, the person attempting to read the LCD
is facing into the sun, and is brightly illuminated. Under 21 these circumstances the reflected image of the person's own 22 face and surroundings, as seen in the window 117, can be 23 extremely bright and can almost totally obscure the LCD.
24 It is believed that the provision of an antireflection coating in our invention is particularly unobvious, for at 26 least three reasons. First, the very existence of the 27 glare problem is much less evident than the problem of 28 temperature control.

1 In our own development of the present invention, all 2 our concern and early tests were directed to verifying that 3 our apparatus would work even with direct sunlight 4 impinging upon and heating the LCD. Therefore prototypes were always tested with the LCD facing toward the sun. We 6 did not realize that we had inadvertently selected a mode 7 of test in which the problem of glare was minimal.
8 On one occasion, when we had not yet perfected the 9 temperature control aspects of our invention, we were asked about the possibility of installing an electronic directory 11 in a north-facing wall. We supposed that such an 12 installation would be uneventful, since direct heat loading 13 in the particular facility could be very low.
14 After positioning a prototype in the subject facility, however, we were quite amazed to discover that the LCD in 16 the prototype was virtually invisible because of glare.
17 Only then did we become aware of this glare problem.
18 There is a second reason that use of antireflection 19 coating is particularly unobvious. The LCD industry has settled upon the use of antireflecting surfaces -- i. e., a 21 matte finish -- on the LCD face.
22 This is the industry's solution to reduction of what 23 little glare is present in use of a laptop computer and the 24 like. Such a finish cannot be used on windows that are spaced forward from the LCD, as we found by actual attempts 26 -- but the common wisdom of the industry in this regard 27 tends to distract attention from alternatives.
28 Another seemingly fruitful avenue was use of a tinted 1 window. Only after a significant effort could we conclude 2 that such a technique was not effective. The tinted window 3 reduced light transmission to and from the LCD, making it 4 too dim to read. What we needed was an antiglare coating that was substantially invisible.
6 It was not through the teaching of the LCD or 7 directory industry, but only by happening to think of a 8 recent personal incident involving a different field, that 9 we came upon the idea of antireflection coatings. More specifically, one of the present inventors had only 11 recently ordered a pair of eyeglasses, and recalled having 12 been offered an antireflection coating at a small added 13 price. He also recalled that this coating was described as 14 untinted and invisible, and he accordingly thought that it might not suffer from the problems of other coatings.
16 There is yet a third reason for characterizing 17 eyeglass-type antireflection coatings as unobvious in 18 connection with the present invention. In our preliminary 19 inquiries regarding the possibility applying such coatings to our windows, we were consistently informed that such 21 application would be prohibitively expensive.
22 The basis for this information was that standard 23 equipment had developed for coating large numbers of 24 eyeglass lenses at once. Further, use for eyeglasses appeared to be the primary segment of the antireflection-26 coating industry. Without extensive modification, such 27 equipment was (and it is) inappropriate for coating viewing 28 windows large enough for an LCD screen.

`- 1 338573 1 ~usiness people who have such equipment were 2 understandably reluctant to invest in such modification on 3 behalf of a new product with unproven market performance.
4 Accordingly we were led to believe that antireflection coating of our windows would be uneconomic.
6 That belief persisted until, after considerable 7 effort, we found a relatively small operator for whom our 8 project represented a significant amount of business. That 9 firm was accordingly willing to undertake the needed modifications.
11 It is possible that with future refinements of 12 fluorescent backlighting in LCDs it may become possible to 13 make the LCD itself so bright as to be clearly visible even 14 in the presence of glare at the viewing window. For the present, however, the provision of substantially invisible 16 antireflection coatings is an important advance.
17 Six metal extenders 205, spaced along the top and 18 bottom edges of the viewing port 111, stand the LCD 120 off 19 from the rear surface of the front panel 102, defining an air space between the viewing window 117 and the LCD 120.
21 These six extenders are fixed behind the panel 102 by six 22 mounting studs.
23 The extenders 205 pass through holes in the top and 24 bottom brackets 121, 122 and in the viewing window 117; and secure the brackets and viewing window in place. From the 26 perspective of a user of the apparatus, the brackets 121, 27 122 hide the extenders from view, providing a finished look 28 to the assembly.

1 The brackets also contour the air-circulation region, 2 to provide for more-nearly laminar air flow. The brackets 3 do not extend along the side edges of this air space, which 4 is accordingly unobstructed at both sides.
A circulating fan 125 is mounted to each side pillar 6 104, 105, along the inward-facing surface of the pillar and 7 near the ceiling 106. These fans 125 are vertically 8 aligned with the LCD 120, roughly, and are aligned in the 9 front-to-back direction so that the front half of each fan 125 is roughly adjacent to the air space formed between the 11 window 117 and LCD 120.
12 Strictly speaking the fans 125 are visible from 13 outside the case 101 by a viewer looking through the window 14 117 at an acute angle to the front panel 102 and window 117. Ordinarily, however, the fans 125 are outside the 16 lines of view of a person standing in front of the device 17 and reading the LCD 120. Moreover, advantageously the fans 18 are of dark-colored material while the screen and the front 19 panel 102 are of light-colored material, so that the fans are quite inconspicuous -- particularly when operating.
21 Each side pillar 104, 105 is a rectangular vertical 22 tube open at the bottom 206, 207, as shown (Fig. 2), 23 apertured at 208, 209 near the top along the inward-facing 24 surface for passage of air through the corresponding fan 125, and unobstructed between the bottom opening 206, 207 26 and the fan aperture 208, 209. Each pillar thus serves 27 double duty as a very sturdy structural member of the case 28 101 and as an air-passage duct or plenum.

1 338~73 1 Depending upon the direction of fan operation, air 2 enters either opening 206 or 207, and is exhausted through 3 the other. For installations where temperature or sun 4 loading is never very high, one or the other fan 125 can be omitted.
6 From the scale established by the standard telephone 7 pushbutton array 116 it can be readily seen that each 8 plenum is too narrow for passage of a person's arm, and 9 contains no apparatus that could be readily damaged by insertion of a bar or other tool from the bottom. Hence 11 the plena are reasonably vandal resistant.
12 Yet they are also straight and unobstructed, and 13 therefore offer a very minimum of resistance to air 14 circulation by the fans 125. Consequently, as mentioned earlier, the fans can be of a particularly low-power, quiet 16 type such as the 1.8-watt, 18-cubic-foot-per-minute model 17 TFDD6012 RXA commercially available from the Toyo 18 Corporation of Japan.
19 Because the openings 206, 207 located at the base of the pillars 104, 105 face downward, rain cannot enter the 21 case through them. Moreover, this arrangement allows the 22 case to be flush-mounted in a wall without disrupting air 23 intake and exhaust.
24 The LCD itself is preferably a Model EG 2402-AR
supertwist type made by Seiko Epson Corporation, or a Model 26 LM 674 XGNR supertwist type, made by Hitachi Corporation.
27 The choice of models depends on whether the number of 28 occupants to be listed on the screen at once can be 1 adequately presented on an eight-line, forty-character 2 screen or justifies use of a sixteen-line, eighty-character 3 screen, respectively.
4 The display can be operated from a microprocessor or even a personal computer or other microcomputer, in very 6 generally conventional fashion. We prefer, however, to use 7 novel electronics and software which we have developed.
8 These additional subsystems optimize the performance of the 9 display as part of a novel programmable electronic directory system, as will be described shortly.
11 Immediately behind the window 117, in the space 12 between the window and the LCD 120, is a thermistor element 13 123, disposed to receive substantially the same 14 radiant-heat loading from incident sunlight as does the LCD
120. This thermistor, perhaps best seen in Fig. 3, is 16 excited and monitored by portions of the electronic 17 circuitry 211 within the case 101, and the resulting 18 temperature information is used to control both the fans 19 and the LCD contrast voltage.
As also shown in Fig. 2, a small strip heater 212 is 21 advantageously mounted behind the LCD 120. This heater too 22 is temperature-controlled; however, it need not be made 23 responsive to the thermistor 123. The heater element 24 itself is self-regulating: its resistance increases with temperature, tending to reduce heat output. The heater can 26 be a twelve-volt d. c. model CDH 00310 commercially 27 available from Midwest Components, Inc. of Muskegon, 28 Michigan.

-~ 338573 Approxlmate dlmenslons (ln lnches) of the apparatus are collected here:
case 101 helght 19 width 15.3 depth 3.8 port 111 height 5.3 width 10.3 window 117 height 6.5 wldth 11 thlckness0.1 plena 104, lOS wldth 0.9 ~plllars) depth 2.9 Thu~ our lnventlon encompasses several lmportant lnnovatlons relatlng to provlslon of a hlgh-resolutlon, hlgh-contrast, essentlally glare-free dlsplay for electronic directories and the like. It ls partlculary advantageous in outdoor lnstallatlons, and ln bulldlng entrles or lobbies where temperature and brlghtness of lllumlnatlon are not well controlled.

Our lnventlon further encompasses important innovatlons ln a programmable electronlc dlrectory system. These innovations will be descrlbed herebelow.
As mentloned earller, prlor to thls inventlon, electronic directory systems had to be programmed at the directory unlt itself or by a computer close by. Our inventlon allows for programming of the directory from a remote location over the telephone llnes uslng a modem and termlnal or by uslng a standard tone-transmittlng telephone by itself. The system can also be programmed locally uslng a handheld programmer 201 ~Flg. 4), the system's keypad 202, or vla the system's RS-232 communlcatlons port 203. Thus, ln addition to provlding both remote and local programmlng capabllltles in the same machine, the system is capable of managlng a multlpllcity of programmlng lnput devlces.
Moreover, the system can be programmed while it ls being used without the programmer or the u~er reallzing the other party ls uslng the machlne. However the system is programmed, names are automatically alphabetized and put in their proper location on the directory.
Flgure 4 glves an overview of the programming processing flow and ~hows the different programming devices that can be used along with the ma~or electronlc components used to process their input. Local programming is generally done using a handheld programmer 201 of our own deslgn (plctured in Fig. 5) whlch plugs dlrectly lnto the system's electronlcs 211 (Flg. 2~ vla a ribbon cable 271. The programmer ls a membrane keypad that slmply provldes contact closure output for alphabetic character~ 272, numerals and other phone-system characters 273, and standard computer-keyboard functions 274, as well as dlrectory and access functlons 275. As a result, lt ls extremely rugged, very thln, small slzed, and very lnexpenslve.
As can be seen from the graphlcs on the keypad, it as well a~ our ~ystem can do substantlally more than provlde for an electronlc dlrectory. In one of lts forms, the system can be a complete access control system provldlng for both occupant and vlsitor access control, uslng card or code entry for occupants and telephone entry for vlsltors. In this system configuratlon, the electronlc dlrectory would normally be part of the telephone entry functlon for vlsltor access control. The mlcrophone 204 (Flg. 2) and the speaker 203 (Flg. 2) are for communlcatlons between the vlsltor and the person belng contacted ln the bulldlng whose name is listed on the electronic dlrectory. This system configuration is, however, only one form in which the electronic dlrectory could be used and in no way is intended to llmlt the scope of our clalms.
The systems 12-button keypad 113/116 ~Flg. 1) and 202 (Fig. 4), whlch also provldes slmple contact closure output, can also be used to program the system locally. In thls lnstance, 2-dlglt number~ are used to encode letters. Whlle the keypad 113/116,202 is more cumbersome for alphanumeric programming, lt is a useful back-up ln case the user has mlsplaced the handheld programmer 201.
The contact closure outputs of the handheld programmer 201 and system keypad 113/116,202 go to separate PIAs (Parallel Interface Adapters) 204, 205 and then via a bus 206 to the systems mlcroprocessor 210. We use a Motorola 6809 mlcroprocessor and Motorola 6821 PIAs. The PIAs 204, 205 serve to expand the available ports on the microprocessor 210 and have hardware "interrupts' ~each being a pin on the chip that is in a high or low state) that alert the microprocessor 210 that data is on the PIA 204 or 205 and ready to be retrleved. Once the microphone 210 ha~ retrieved that data from a single keypress lt loads it lnto RAM (random access memory~ 211 and dlsplays it on the LCD 220 (120 in Figs. lff.) as it does programming prompts and messages. When the data entry from one or more keypresses has been completed it ls then loaded into an EEPROM (electrlcally erasable programmable read only memory) 212 where lt wlll reside untll erased. We use an EEPROM for permanent memory because of its nonvolatillty - the abillty to keep its memory contents wlthout any external power.
The EEPROM 212 we use iB a Samsung 2864.
The thlrd method of local programmlng i8 vla the systems RS-232 port 203 uslng any RS-232 compatlble devlce (e q., a terminal 207). Since the baud rate on the systems RS-232 port 203 ls selectable (300, 1200, 2400, and 4800), the port will accommodate a wlde range of devlces 207. The serial ASCII data that come~ lnto the R~-232 connectlon 203 goes to a UART
(Universal Asynchronous Receiver Transmitter) 208, whlch converts the serlal data to parallel data and also has a hardware interrupt to alert the microprocessor 210 that the UART 208 has data. We use Motorola 6850 UART. The microprocessor handles the data the same as it does from the handheld programmer 201 and keypad 202, except that lt displays the data on the devlce 207 connected to the RS-232 port 203 ~e q., the terminals 207 video screen).
The RS-232 port 203 also provides a means of remote programming in that a modem 231 can be connected to the RS-232 port 203 and thus allow communicatlons with the system over the . _ . . .. . .. .

telephone lines 232 from a remote locatlon havlng a modem and termlnal 233. Our system also has an onboard 300-baud modem chip (Natlonal 74HC943) 234 whlch e~lmlnate~ the need for an outboard modem 231. An outboard modem 231 would be used only if a faster than 300-baud data transmis~lon rate was de~lred. A "dumb"
terminal 207, 233 as oppo~ed to a personal computer ~PC) can be used in either case since all the necessary intelllgence resldes in our system.
The serial ASCII data from the onboard modem 234 ls sent to a UAR~ 235 and then to the mlcroproce~sor 210. Data entries and system prompts are sent back to the modem 234 -- whlch then transmlts them over the telephone llne 236 to the modem and terminal 233 at the remote location where they are displayed on the terminal~ video screen.
A standard tone telephone 241 can also be used to program the system from a remote locatlon. The DTMF (Dual Tone Multi Frequency) tones are received by a tone decoder chip (Mltel 8870) 242 in the systems electronics, which chlp 242 decodes the frequencles by comparing them to a crystal oscillating at 3.579545 MHZ. The decoder chlp 242 repre~ents the decoded frequency in dlgltal form, whlch ls then sènt through a PIA 243 to the mlcroprocessor 210. The decoder chip 242 has a hardware interrupt, as doe~ the PIA 243 for notlfication that data are ready for tran~mission. The mlcroprocessor 210 processes the data as before except that lnstead of data and prompts being displayed on a screen, a voice chlp (SSI-263) 244 generates syntheslzed volce responses and prompts 245 which are ~ent back over the prevlously mentloned telephone llne 236 to the phone 241 and human programmer at the remote locatlon.
The ablllty ln the same electronlc dlrectory unlt to be programmed vla modem 234, 233 or by tone telephone 241, uslng just one telephone llne 236 for the syBtem~ 18 not stralghtforward and 16 another novel aspect of our lnventlon. As far as we are aware, all other systems, wlth both means of programmlng ~not other electronlc dlrectory systems whlch have nelther capablllty) require two telephone lines, one for modem programmlng and the other for tone programmlng (e.a., electronlc banklng systems).
The dlfflculty ls that a means of sortlng the lncomlng signal types from a common input source is needed. The source in this ca~e 18 the unknown type of telephone call belng answered.
We accompllsh thls by u~lng an actlve hybrld clrcult 246. The hybrld ls an analog three-port clrcult deslgn havlng an lnput port 247, 247', an output 248, 248', and an input/output port 249 that enables the concurrent testing for elther an lncomlng modem ~lgnal or a DTMF slgnal. The modem 234 transmitter~ sectlon and voice chlps 244 outputs are fed to the input port 247 and both the modem 234 recelver sectlon and the DTMF recelvers 242 lnputs are connected to the hybrlds 246 output port 248, 248'. The telephone-llne 236 lnterface feeds signals both into and out of the active hybrlds 246 lnput/output port 249.
When the sy~tem ls called, it senses the ring signal on the llne 236 and lntegrates these occurrences over a perlod of time to avold falsely answerlng on nolse pul~es. The system then answers by selzlng the line 236 and, after a 2.2 second delay, ` - -answers ln English speech 245, saylng, "Hello." It then presents the modem 234 answering tone and "llstens" concurrently for either an orig~nate tone from a possible modem or origlnatlng statlon 233 or a DTMF tone from a possible phone 241. If an origlnate tone from a modem 233 is detected, the unlt wlll ignore subsequent DTMF
tones. Conversely, if a DTMF tone ls detected, the Infinity unlt turns off lts modem 234 answering tone, lgnores any subsequent modem frequencles, and obeys only the lncoming DTMF commands.
Another feature of the active hybrid 246 is the cancellatlon of leakage between the input port (transmltter output) 247, 247' and the output port (receiver input) 248, 248'.
This is accomplished by the mathematlcs inherent in the design.
When the sidetone balance (the relative impedance of the system vs. the phone line 236) ls adjusted properly, a close impedance match to the telephone is achieved and a high degree of output-to-input leakage suppresslon results. Thls condition makes it po~sible for multlplexlng both the modem 234 and the DTMF receiver 242 on the same telephone line 236, since the modems 234 transmltter cannot overpower the sensitive DTMF receivers 242 lnput ~tage.
Flnally, as mentioned earller, one of the forms of our electronlc dlrectory system ls as part of an access control system. When used in thls conflguratlon, the system has a buffer memory (part of RAM 211) capable of automatlcally storlng the last several thousand transactions. Transactions include entrie6 made using cards or codes, entries granted by telephone, as well as alarm condltions and the llke. If the transactlon buffer ls filled, the oldest transactlon ls deleted when a new transactlon ls entered. The lnformation recorded for each transaction lncludes the tlme, date, type of transactlon, entry polnt, card or code used, attached name, and action taken (e.g., access granted or denled).
Our system allows these data to be retrieved when the system is ln the programmlng mode, elther locally 201-208 or remotely 231-249, with the data dlsplayed on the systems LCD 220, a prlnter ~not shown), or a terminal 207, 233, dependlng on the programmlng mode as dlscussed earller. The chlp (part of ~AM 211) we use for the transactlon buffer memory ls an RCA 6264 elght-thousand byte RAM or a RCA 62256 thlrty-two thousand byte RAM.
The size depends on the maximum number of transactlons wlshed to be retalned.
We have also created a software proqram on floppy dlsk that allows the data ln the transactlon buffer to be sorted after lt 1~ retrieved. Sortlng can be by date and tlme, 60urce and type of transactlon, code used, name, and action taken. Thus, a user can focus ln more narrowly on the speclflc transactlons he wlshes to revlew.
The program also allows the programmed lnformatlon stored in the systems EEPROM memory 212 (e q., names on the dlrectory, codes, telephone numbers, etc.) to be downloaded to a floppy dlsk. Thus, a back-up dlsk flle of the systems memory can be malntained. This ls a particulary attractive feature wlth dlrectory unlts havlng the capaclty for a large number of names, where loss of the systems memory (e a., due to llghtnlng strlke) 1 3 3 8 ~ 73 74593-1 would necessltate reprogrammlng many names. Wlth thls floppy dlsk program, the names on the back-up disk file can simply be uploaded to the affected ~y~tem once lt is back in comml~slon.
This floppy dlsk program can be used in any IBM-compatible PCs wlth DOS 2.0 or hlgher. The PC can be connected dlrectly to the syYtem vla RS-232 connection 203 or lt can communlcate wlth the sy~tem via modem 231, 234 slnce the floppy dlsk program lncludes the termlnal emulatlon and communlcatlons software necessary for a PC to be able to communicate via modem lo 231, 234.
It wlll be under6tood that the foregoing dlsclosure ls lntended to be merely exemplary, and not to llmlt the scope of the lnvention -- whlch is to be determined by reference to the appended clalms.

Claims (36)

1. A telephone-entry system for use by a visitor to a facility having multiple individual-occupant entities, and having telephone service, and having individual telephone outlets at the individual-occupant entities respectively; said system comprising:
a microphone and audio speaker, disposed for use by such visitor when seeking access, for voice communication between such visitor and an occupant of such individual-occupant entity;
electrical communication-circuit means, interconnected with the microphone and audio speaker, for effectuating said voice communication through one of such individual telephone outlets by carrying electrical signals between (1) the microphone and speaker and (2) such telephone service;
manually operable controls, disposed for use by such visitor;
electronic memory means for holding directory information for such facility, particularly including names of such individual-occupant entities;
a liquid-crystal display, disposed for viewing by such visitor, and having a display medium and a structure for containing the display medium; said liquid-crystal display structure comprising a face, disposed in front of the medium, for displaying the directory information; and at least one digital electronic microprocessor, electrically interconnected with and responsive to the manually operable controls, and electrically interconnected with the electrical communication-circuit means, the memory means and the liquid-crystal display, for:
reading the directory information from the memory means, controlling the liquid-crystal display to exhibit the directory information;
controlling the sequence of directory-information exhibition by the liquid-crystal display, and controlling the electronic communication-circuit means to initiate communication, via such telephone service, with a particular individual-occupant entity selected by such visitor from the directory information displayed by the liquid-crystal display.

2. The system of claim 1, for use with a facility that has means, such as an electrically operated door lock and electrical control wires leading therefrom, for granting or denying physical access to the facility; further comprising:
means forming a portion of the at least one microprocessor for developing an access-decision signal, in response to a command signal from an occupant entity selected by such visitor from the directory information displayed by the liquid-crystal display; and signal-conversion means, responsive to the at least one microprocessor access-decision signal, for generating an operating signal in correspondence with the access-decision signal to actuate such access-granting-or-denying means.

3. The system of claim 2, wherein:

the signal-conversion means comprise an electrical relay; and the system further comprises electrical wiring means, connected to the relay, for connection to the access-granting-or-denying means.

4. The system of claim 3, wherein:
the at least one microprocessor is responsive to signals, via the communication-circuit means, originating at the individual-occupant entity selected by such visitor from the directory information displayed by the liquid-crystal display; and the at least one microprocessor responds to the occupant-entity signals by controlling actuation of the relay.

5. The system of claim 4, wherein:
the at least one microprocessor controls actuation of the relay by developing said access-decision signal.

6. The system of claim 1, wherein:
the displayed directory information comprises the names of individual-occupant entities included in the directory;
the at least one microprocessor comprises means for responding to a selection of an individual-occupant entity by such visitor, when such visitor makes said selection by --selecting the name of an individual-occupant entity from the displayed directory information, and then using the manually operable controls to actuate establishment of communication with the selected individual-occupant entity; and the at least one microprocessor response to said selection comprises effecting communication, via such telephone service, with the selected individual-occupant entity.

7. The system of claim 6, wherein:
the manually operable controls include plural electrical pushbutton keys.

8. The system of claim 7, wherein:
at least some of the keys are in the form of a keypad, each key in the keypad bearing character indicia.

9. The system of claim 8, wherein:
the displayed directory information further comprises, in association with the individual-occupant-entity name, character indicia such as respective numerical codes for use in telephoning the associated individual-occupant entities included in the directory; and the visitor uses the keypad to actuate the establishing of communication with an individual-occupant entity, by pressing keys bearing particular character indicia corresponding to the individual-occupant entity.

10. The system of claim 1, further comprising:
a protective window spaced in front of the liquid-crystal display.

11. The system of claim 10, further comprising:
substantially nonattenuating means, applied to the window, for reducing visible glare arising in reflection at the window.

12. The system of claim 11, wherein:
the glare-reducing means comprise an antireflection coating on the viewing window.

13. The system of claim 1, wherein:
the at least one microprocessor further comprises means for writing the directory information to the memory means.

14. The system of claim 13, wherein:
the at least one microprocessor further comprises means for automatically alphabetizing directory information displayed on the liquid-crystal display.

15. The system of claim 1, further comprising:
means for programming information into the memory means from a remote location.

16. The system of claim 15, further comprising:

means for returning acknowledgement signals to the remote location.

17. The system of claim 16, wherein:
the information-programming means receive information via the electrical communication-circuit means.

18. The system of claim 17, wherein:
the information-programming means receive information via the electrical communication-circuit means even when said circuit means are in use for communication between a visitor and an occupant.

19. The system of claim 18, wherein:
the information-programming means receive information via the electrical communication-circuit means by data multiplexing with voice communication.

20. The system of claim 16, wherein:
the information received by the programming means comprises directory information.

21. The system of claim 20, also for use in controlling access to the facility by a purported occupant of the facility, and further comprising:
means for evaluating access codes presented to the system by such purported occupant; and wherein:
the information received by the programming means further comprises access-code information.

22. The system of claim 2, further comprising:
means for revising, from a location remote from the at least one microprocessor, information held in the memory means.

23. The system of claim 2, particulary for use by a visitor to a facility having telephone service in the form of public-subscriber telephone service; and wherein:
said circuit means comprise means for effectuating said voice communication by carrying electrical signals between (1) the microphone and speaker and (2) such public-subscriber telephone service.

24. A telephone-entry system for use by a visitor to a facility having multiple individual-occupant entities, and having telephone-system service, and having individual telephone outlets at the individual-occupant entities respectively; said system comprising:
a microphone and audio speaker, disposed for use by such visitor when seeking access, for voice communication between such visitor and an occupant of such individual-occupant entity;
electrical communication-circuit means, interconnected with the microphone and audio speaker, for effectuating said voice communication through one of such individual telephone outlets by carrying electrical signals between (1) the microphone and speaker and (2) such telephone service;
manually operable controls, disposed for use by such visitor;
electronic memory means for holding directory information for such facility, particularly including names of such individual-occupant entities;

a display, disposed for viewing by such visitor, for displaying the directory information;
at least one digital electronic microprocessor, electrically interconnected with and responsive to the manually operable controls, and electrically interconnected with the electrical communication-circuit means, the memory means and the display, for:
reading the directory information from the memory means, controlling the display to exhibit the directory information, controlling the sequence of directory-information exhibition by the display, and controlling the electronic communication-circuit means to initiate communication, via such telephone service, with a particular individual-occupant entity selected by such visitor from the directory information displayed by the display; and means for programming, remotely from the control means and at least one microprocessor, the directory information held in the electronic memory means.

25. The system of claim 24, wherein the programming means comprise:
a modem electrically interconnected with the at least one digital electronic microprocessor and with the communication-circuit means, for transmitting signals between the at least one microprocessor and communication-circuit means; and means, forming a part of the at least one digital electronic microprocessor, for:

communication with the modem, receiving remotely provided directory information via the modem, to store in the electronic memory means, and storing the received directory information in the electronic memory means.

26. The system of claim 25, also for use with a separate local handheld programming device, and wherein the programming means further comprise:
programmer-port means, interconnected with the at least one microprocessor and temporarily interconnected with such local handheld programming device, for receiving directory-information and storage-command signals from such handheld programming device and directing these signals to the at least one microprocessor.

27. The system of claim 26, further for use with a terminal at the facility, and wherein the programming means further comprise:
a cable connector for electrical interconnection by cable with such terminal at such facility; and a computer communication port, interconnected with the at least one microprocessor and with the cable connector, for:
receiving directory information signals from such terminal via the cable connector, and directing these signals to the at least one microprocessor for storage of the information in the electronic memory means.

28. The system of claim 27, wherein the programming means further comprise:
DTMF-decoding means, interconnected with the at least one microprocessor and with the communication-circuit means, for:
reception, from the communication-circuit means, and DTMF-decoding of remotely provided directory information and storage commands in the form of DTMF tones, and directing corresponding DTMF-decoded directory-information and storage-command signals to the at least one microprocessor; and means, forming a part of the at least one digital electronic microprocessor, for:
receiving the DTMF-decoded directory-information and storage-command signals from the DTMF-decoding means, and storing the received directory information in the electronic memory means.

29. The system of claim 28, further comprising:
a voice chip, electrically interconnected with and controlled by the at least one microprocessor and electrically interconnected with the communication-circuit means, for receiving acknowledgement signals from the at least one microprocessor and directing them, in the form of speech, to the communication-circuit means.

30. The system of claim 28, further comprising:
means for returning acknowledgement signals for the signals from the DTMF-decoding means.

31. The system of claim 27, wherein the computer communication port further comprises:
means for returning acknowledgment signals from the at least one microprocessor to such terminal at such facility, via the cable connector.

32. The system of claim 25, further comprising:
means for returning acknowledgement signals via the modem.

33. The system of claim 24, for use with a separate local handheld programming device, and wherein:
the programming means comprise programmer-port means, interconnected with the at least one microprocessor and temporarily interconnected with such local handheld programming device, for transmitting signals to the at least one microprocessor from the programming device, so as to receive directory-information and storage-command signals from such handheld programming device and direct these signals to the at least one microprocessor; and the system further comprises means, forming a part of the at least one digital electronic microprocessor, for:
receiving remotely provided directory information via the programmer port, to store in the electronic memory means, and storing this received directory information in the electronic memory means.

34. The system of claim 24, further for use with a programming terminal at the facility, and wherein the programming means further comprise:
a cable connector for electrical interconnection by cable with such programming terminal at such facility; and a computer communication port, interconnected with the at least one microprocessor and with the cable connector, for:
receiving directory information signals from such programming terminal via the cable connector, and directing these signals to the at least one microprocessor for storage of the information in the electronic memory means.

35. The system of claim 24, wherein the programming means further comprise:
DTMF-decoding means, interconnected with the at least one microprocessor and with the communication-circuit means, for:
reception, from the communication-circuit means, and DTMF-decoding of remotely provided directory information and storage commands in the form of DTMF tones, and directing corresponding DTMF-decoded directory-information and storage-command signals to the at least one microprocessor; and means, forming a part of the at least one digital electronic microprocessor, for:
receiving the DTMF-decoded directory-information and storage-command signals from the DTMF-decoding means, and storing the received directory information in the electronic memory means.

36. The system of claim 35, further comprising:
a voice chip, electrically interconnected with and controlled by the at least one microprocessor, and electrically interconnected with the communication-circuit means, for receiving acknowledgement signals from the at least one microprocessor and directing them, in the form of speech, to the communication-circuit means.