Automatic hand-supportable laser bar code symbol scanner and method of reading bar code symbols using the same

• US 6,328,211 B1
• Filed: 07/24/1997
• Issued: 12/11/2001
• Est. Priority Date: 09/17/1990
• Status: Expired due to Fees

• Current Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Original Assignee: Metrologic Instruments Incorporated (Honeywell International Inc.)
• Inventors: Wilz, David M. Sr., Rockstein, George B., Knowles, Carl H.
• Primary Examiner(s): Pitts, Harold I.
• Application Number:
  US08/899,977
• Time in Patent Office: 1,601 Days
• Field of Search: 235/462.01, 235/462.3, 235/462.31, 235/462.45, 235/472.01
• US Class Current: 235/462.01
• CPC Class Codes: G06K 17/0022 arrangements or provisious for transferring data to distant stations, e.g. from a sensing device "transfer between computer elements G06F13/00 "; data-transmission H04L
• CPC Class Codes: G06K 2207/1012 Special detection of object
• CPC Class Codes: G06K 2207/1016 Motor control or optical moving unit control
• CPC Class Codes: G06K 2207/1017 Programmable
• CPC Class Codes: G06K 2207/1018 Source control
• CPC Class Codes: G06K 7/10564 Light sources
• CPC Class Codes: G06K 7/10584 Source control
• CPC Class Codes: G06K 7/10594 Beam path
• CPC Class Codes: G06K 7/10603 Basic scanning using moving elements
• CPC Class Codes: G06K 7/10693 for omnidirectional scanning
• CPC Class Codes: G06K 7/10702 Particularities of propagating elements, e.g. lenses, mirrors G06K7/10831 takes precedence
• CPC Class Codes: G06K 7/10792 Special measures in relation to the object to be scanned
• CPC Class Codes: G06K 7/10801 Multidistance reading
• CPC Class Codes: G06K 7/10851 Circuits for pulse shaping, amplifying, eliminating noise signals, checking the function of the sensing device basic electronic circuitry H03
• CPC Class Codes: G06K 7/10871 randomly oriented data-fields, code-marks therefore, e.g. concentric circles-code
• CPC Class Codes: G06K 7/10881 constructional details of hand-held scanners
• CPC Class Codes: G06K 7/10891 the scanner to be worn on a finger or on a wrist
• CPC Class Codes: G06K 7/109 adaptations to make the hand-held scanner useable as a fixed scanner
• CPC Class Codes: G06K 7/14 using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence
• CPC Class Codes: G06K 7/1443 locating of the code in an image

Abstract

An automatic bar code symbol reading system comprising components for carrying out object detection, scanning, photoreceiving, A/D conversion, bar code presence detection, symbol decoding, data format conversion, data storage and data transmission functions. In general, the automatic bar code symbol reading device includes a manually actuatable read-repeat switch and control system having a plurality of control centers that control the operation of the system components in accordance with preselected system control operations. Each of the control centers are responsive to control activation signals generated by certain of the system components upon the occurrence of predefined conditions. Certain of the control centers are capable overriding other control centers to provide diverse control capabilities which facilitates execution of intelligent operations and power conservation, during bar code symbol reading. In combination, control system and read-repeat switch enable the device to automatically read a previously read bar code symbol once again, or retransmit or restore symbol character data of a previously read bar code symbol, each time the read-repeat switch is depressed during the system control process of the present invention. This simple procedure can be repeated time and time again to read, in a user-controllable fashion, the same bar code symbol any number of times.

Claims

1. An automatic bar code symbol system having a selectable mode of operation in which a bar code symbol can be selectively read one or more times, said system comprising:

a hand-supportable housing having a light transmission aperture through which visible light can exit from and enter into said hand-supportable housing;

laser beam producing means, disposed in said hand-supportable housing, for producing a visible laser beam within said hand-supportable housing;

laser beam scanning means, disposed in said hand-supportable housing, for repeatedly scanning said visible laser beam across a scan field defined external to said hand-supportable housing and across a bar code symbol supported on an object located in at least a portion of said scan field;

laser light detecting means, disposed in said hand-supportable housing, for detecting the intensity of visible laser light reflected off said bar code symbol and passing through said light transmission aperture as said visible laser beam is repeatedly scanned across said bar code symbol present in said scan field, and for automatically producing scan data indicative of said detected intensity;

a manually actuatable switch for generating a read-repeat signal representative of a request by the user of said systems, to detect and decode once again a previously detected and decoded bar code symbol;

scan data processing means for processing produced scan data in order to detect and decode said bar code symbol when said bar code symbol is present in said scan field and automatically produce symbol character data in a form representative of said decoded bar code symbol and suitable for transmission to a symbol character data storage means,

said scan data processing means automatically detecting the generation of said signal, prior to said scan data processing means automatically processing produced scan data so as to detect and decode said decoded bar code symbol once again, and thereafter produce once again symbol character data in a form representative of said decoded bar code symbol; and

control means for automatically controlling the operation of said laser beam producing means and said scan data processing means so that said bar code symbol is detected and decoded as said visible laser beam is repeatedly scanned across said bar code symbol present in said scan field, and after said signal processing means detects the generation of said signal, said scan data processing means automatically processes produced scan data in order to detect and decode said decoded bar code symbol once again, and thereafter automatically produces once again said symbol character representative of said decoded bar code symbol, and suitable for transmission once again to said symbol character data storage means.

2. The system of claim 1, wherein said laser beam producing means comprises a laser diode.

3. The system of claim 1, wherein said bar code symbol has first and second envelope borders, and wherein said scan data processing means detects the presence of said bar code symbol in said scan field by processing produced scan data so as to detect the first and second envelope borders of said bar code symbol.

4. The system of claim 1, wherein said hand-supportable housing comprises a head portion and a handle portion, and wherein said laser beam producing means, said laser beam scanning means, and said laser light detecting means are disposed in said head portion.

5. The system of claim 1, wherein said scan data processing means, and said control means are disposed within said hand-supportable housing.

6. The system of claim 5, which further comprises a data output port for transmitting said symbol character data to said symbol character data storage means disposed external to said hand-supportable housing.

7. The system of claim 6, which further comprises a flexible connector cable physically associated with said data output port, for transmitting said bar code symbol data to said symbol character data storage means.

9. The system of claim 1, wherein said laser beam producing means comprises a laser diode.

10. The system of claim 1, wherein said bar code symbol has first and second envelope borders, and wherein said scan data processing means detects the presence of said bar code symbol in said scan field by processing produced scan data so as to detect the first and second envelope borders of said bar code symbol.

11. The system of claim 1, wherein said hand-supportable housing comprises a head portion and a handle portion, and wherein said laser beam producing means, said laser beam scanning means, and said laser light detecting means are disposed in said head portion.

12. The system of claim 1, wherein said scan data processing means, and said control means are disposed within said hand-supportable housing.

13. The system of claim 5, which further comprises a data output port for transmitting said symbol character data to said symbol character data storage means disposed external to said hand-supportable housing.

14. The system of claim 6, which further comprises a flexible connector cable physically associated with said data output port, for transmitting said bar code symbol data to said symbol character data storage means.

8. An automatic bar code symbol system having a selectable mode of operation in which a bar code symbol can be selectively read one or more times, said system comprising:

a hand-supportable housing having a light transmission aperture through which visible light can exit from and enter into said hand-supportable housing;

laser beam producing means, disposed in said hand-supportable housing, for producing a visible laser beam within said hand-supportable housing;

laser beam scanning means, disposed in said hand-supportable housing, for repeatedly scanning said visible laser beam across a scan field defined external to said hand-supportable housing and across a bar code symbol supported on an object located in at least a portion of said scan field;

laser light detecting means, disposed in said hand-supportable housing, for detecting the intensity of visible laser light reflected off said bar code symbol and passing through said light transmission aperture as said visible laser beam is repeatedly scanned across said bar code symbol present in said scan field, and for automatically producing scan data indicative of said detected intensity;

a manually actuatable switch for generating a signal representative of a request to produce once again symbol character data representative of a previously detected and decoded bar code symbol by the user of said system;

scan data processing means for processing produced scan data in order to detect and decode said bar code symbol when said bar code symbol is present in said scan field and automatically produce symbol character data in a form representative of said decoded bar code symbol and suitable for transmission to a symbol character data storage means,

said scan data processing means automatically detecting the generation of said signal, prior to said scan data processing means automatically producing once again, and thereafter produce once again symbol character data in a form representative of said decoded bar code symbol; and

control means for automatically controlling the operation of said laser beam producing means and said scan data processing means so that said bar code symbol is detected and decoded as said visible laser beam is repeatedly scanned across said bar code symbol present in said scan field, and after said scan data processing means detects the generation of said signal, said scan data processing means automatically produces once again said symbol character representative of said decoded bar code symbol and suitable for transmission once again to said symbol character data storage means.

15. A method of selectively reading a bar code symbol one or more times using an automatic hand-supportable unit, comprising the sequence of steps:

(a) manually supporting said automatic hand-supportable unit adjacent an object supporting a bar code symbol so that said object is located within at least a portion of a scan field defined external to said automatic hand-supportable unit, and said automatic hand-supportable unit is disposed in a substantially non-contacting relationship with said object;

(b) automatically producing a visible laser beam from a laser beam producing source disposed in said automatic hand-supportable unit, and repeatedly scanning said visible laser beam through a light transmission aperture in said automatic hand-supportable unit and across said bar code symbol while said bar code symbol is present in said scan field;

(c) automatically detecting at said automatic hand-supportable unit, the intensity of visible laser light reflected off said bar code symbol, and automatically producing scan data indicative of said detected intensity of visible laser light reflected off said bar code symbol;

(d) automatically processing scan data produced in step (c) in order to detect and decode said bar code symbol present in said scan field, and upon detecting and decoding said bar code symbol, automatically producing symbol character data in a form representative of said decoded bar code symbol and suitable for transmission to a symbol character data storage means operably associated with said hand-supportable unit;

(e) manually actuating a switch operably associated with said hand-supportable housing, in order to generate a signal indicative of a request by the user, for said hand-supportable unit to automatically read once again the bar code symbol which has decoded during step (d);

(f) automatically producing said visible laser beam from said laser beam producing source, and repeatedly scanning said visible laser beam through said light transmission aperture and across said bar code symbol present once again in said scan field;

(g) automatically detecting at said automatic hand-supportable unit, the intensity of visible laser light reflected off said decoded bar code symbol, and automatically producing scan data indicative of said detected intensity of visible laser light of the decoded bar code symbol;

(h) in response to the generation of said signal, automatically processing scan data produced in step (g) in order to detect and decode once again said decoded bar code symbol, and upon detecting and decoding said decoded bar code symbol, automatically producing once again symbol character data in a form representative of said decoded bar code symbol and suitable for transmission to said symbol character data storage means.

16. The method of claim 15, where in steps (d) and (h), said scan data is processed by a scan data processor disposed in said automatic hand-supportable unit.

17. The method of claim 15, where in steps (b) and (h), said visible laser beam is produced by a laser diode disposed in said automatic hand-supportable unit.

18. The method of claim 15, wherein said bar code symbol has first and second envelope borders, and where in step (d) the presence of said bar code symbol in said scan field is detected by processing produced scan data so as to detect the first and second envelope borders of said bar code symbol.

19. The method of claim 15, wherein said automatic hand-supportable unit comprises a housing having a head portion and a handle portion.

21. The method of claim 15, where in step (d), said scan data is processed by a scan data processor disposed in said automatic hand-supportable unit.

22. The method of claim 15, where in step (b), said visible laser beam is produced by a laser diode disposed in said automatic hand-supportable unit.

23. The method of claim 15, wherein said bar code symbol has first and second envelope borders, and where in step (d) the presence of said bar code symbol in said scan field is detected by processing produced scan data so as to detect the first and second envelope borders of said bar code symbol.

24. The method of claim 15, wherein said automatic hand-supportable unit comprises a housing having a head portion and a handle portion.

20. A method of selectively reading a bar code symbol one or more times using an automatic hand-supportable unit, comprising the sequence of steps:

(a) manually supporting said automatic hand-supportable unit adjacent an object supporting a bar code symbol so that said object is located within at least a portion of a scan field defined external to said automatic hand-supportable unit, and said automatic hand-supportable unit is disposed in a substantially non-contacting relationship with said object;

(b) automatically producing a visible laser beam from a laser beam producing source disposed in said automatic hand-supportable unit, and repeatedly scanning said visible laser beam through a light transmission aperture in said automatic hand-supportable unit and across said bar code symbol while said bar code symbol is present in said scan field;

(c) automatically detecting at said automatic hand-supportable unit, the intensity of visible laser light reflected off said bar code symbol, and automatically producing scan data indicative of said detected intensity of visible laser light reflected off said bar code symbol;

(d) automatically processing scan data produced in step (c) in order to detect and decode said bar code symbol present in said scan field, and upon detecting and decoding said bar code symbol, automatically producing symbol character data in a form representative of said decoded bar code symbol and suitable for transmission to a symbol character data storage means operably associated with said hand-supportable unit;

(e) manually actuating a switch operably associated with said hand-supportable housing, in order to generate a signal indicative of a request by the user, for said hand-supportable unit to automatically produce once again symbol character data which was produced during step (d);

(f) in response to the generation of said read-repeat signal produced during step (d), automatically producing once again symbol character data in a form representative of said decoded bar code symbol and suitable for transmission to said symbol character data storage means.

25. An automatic bar code symbol reading system, comprising:

a hand-supportable housing having a light transmission aperture through which visible light can exit and enter said hand-supportable housing;

object detection means in said hand-supportable housing, for transmitting a pulsed infra-red light signal from adjacent said aperture, outwardly into at least a portion of a scan field defined external to said hand-supportable housing, and for automatically generating a first signal in response to the detection of said transmitted infra-red light signal reflected off an object located in said scan field;

scanning means in said hand-supportable housing, for producing a visible light beam within said hand-supportable housing and for directing said visible light beam through said light transmission aperture, and repeatedly scanning said visible light beam across said scan field and a bar code symbol on said detected object;

light detection means in said hand-supportable housing, for detecting the intensity of light reflected off said bar code symbol and passing through said light transmission aperture, and automatically producing scan data indicative of the detected light intensity;

first activatable processing means for processing produced scan data so as to detect said bar code symbol on said detected object, and automatically generating a second signal in response to the detection of said bar code symbol on said detected object;

second activatable processing means for processing produced scan data so as to decode said detected bar code symbol, and automatically producing symbol character data representative of said decoded symbol in response to the decoding of said detected bar code symbol;

manually actuatable means for generating a third signal representative of a request by the user of said automatic bar code symbol reading system, to decode once again said bar code symbol; and

system control means for controlling the operation of said automatic bar code symbol reading system using first, second and third signals, said system control means including

first control means for controlling the operation of said object detection means,

second control means for automatically activating said scanning means, said light detection means and said first activatable processing means for up to a first predetermined time period in response to the generation of said first signal, and

third control means for automatically activating said scanning means, said light detection means and said second activatable processing means for up to a second predetermined time period in response to the generation of said second signal.

26. The automatic bar code symbol reading system of claim 25, wherein said visible light beam is a visible laser beam, and wherein said scanning means comprises

a laser diode disposed in said hand-supportable housing for producing said visible laser beam, and

an electrically driven scanning element for repeatedly scanning said laser beam across said scan field and said bar code symbol on said detected object.

27. The automatic bar code symbol reading system of claim 25, wherein second control means further comprises

means for automatically deactivating said scanning means, said light detection means and said first activatable processing means in response to said first activatable processing means failing to generate said second signal within said first predetermined time period.

28. The automatic bar code symbol reading system of claim 27, wherein said third control means further comprises means for automatically deactivating said scanning means, said light detection means and said second activatable processing means in response to said second activatable processing means failing to decode said detected bar code symbol on said detected object within said second predetermined time period.

29. The automatic bar code symbol reading system of claim 28, wherein said third control means overrides the control operation of said second control means in response to said first processing means generating said second signal.

30. The automatic bar code symbol reading system of claim 29, wherein said third activatable processing means comprises a programmed microprocessor.

31. The automatic bar code symbol reading system of claim 30, wherein said first control means and said second control means comprise first and second control circuits, respectively.

32. The automatic bar code symbol reading system of claim 25, wherein said hand-supportable housing comprises a head portion and handle portion, and wherein said object detection means and said scanning means are disposed in said head portion.

33. An automatic bar code symbol reading system, comprising:

a hand-supportable housing having a light transmission aperture through which visible light can exit and enter said hand-supportable housing;

object detection means in said hand-supportable housing, for automatically detecting an object located in at least in a portion of a scan field defined external to said hand-supportable housing, said object detection means including means for receiving energy from said scan field and means for automatically generating a first signal in response to the detection of energy reflected off an object located in said scan field;

scan data producing means in said hand-supportable housing for producing scan data from said detected object located in said scan field, said scan data producing means including

laser beam generating means for generating a visible laser beam within said hand-supportable housing,

laser beam scanning means for projecting said visible laser beam through said light transmission aperture and for repeatedly scanning said visible laser beam across said scan field and a bar code symbol on said detected object, and

laser light detecting means for detecting the intensity of laser light reflected off said bar code symbol and passing through said light transmission aperture, and for automatically producing scan data indicative of said detected intensity;

first activatable processing means for processing produced scan data so as to detect said bar code symbol on said detected object, and automatically generating a second signal in response to the detection of said bar code symbol;

second activatable processing means for processing produced scan data so as to decode said detected bar code symbol, and automatically producing symbol character data representative of said decoded bar code symbol in response to the decoding of said detected bar code symbol;

manually-actuatable means for generating a third signal representative of a request by the user of said automatic bar code symbol reading system, to produce once again symbol character data representative of said detected and decoded bar code symbol; and

system control means for controlling the operation of said automatic bar code symbol reading system using said first, second and third signals.

34. An automatic bar code symbol reading system, comprising:

a hand-supportable housing having a light transmission aperture through which visible light can exit and enter said hand-supportable housing;

object detection means in said hand-supportable housing, for automatically detecting an object located in at least in a portion of a scan field defined external to said hand-supportable housing, said object detection means including means for receiving energy from said scan field and means for automatically generating a first signal in response to the detection of energy reflected off an object located in said scan field;

scan data producing means in said hand-supportable housing for producing scan data from said detected object located in said scan field, said scan data producing means including

laser beam generating means for generating a visible laser beam within said hand-supportable housing,

laser beam scanning means for projecting said visible laser beam through said light transmission aperture and for repeatedly scanning said visible laser beam across said scan field and a bar code symbol on said detected object, and

laser light detecting means for detecting the intensity of laser light reflected off said bar code symbol and passing through said light transmission aperture, and for automatically producing scan data indicative of said detected intensity;

first activatable processing means for processing produced scan data so as to detect said bar code symbol on said detected object, and automatically generating a second signal in response to the detection of said bar code symbol;

second activatable processing means for processing produced scan data so as to decode said detected bar code symbol, and automatically producing symbol character data representative of said decoded bar code symbol in response to the decoding of said detected bar code symbol;

manually-actuatable means for generating a third signal representative of a request by the user of said automatic bar code symbol reading system, to decode once again said detected and decoded bar code symbol; and

system control means for controlling the operation of said automatic bar code symbol reading system using said first, second and third signals.

35. An automatic bar code symbol reading system, comprising:

a hand-supportable housing having a light transmission aperture through which visible light can exit and enter said hand-supportable housing;

an object detection means in said hand-supportable housing automatically generating an activation signal in response to the detection of an object located within at least a portion of a scan field defined external to said hand-supportable housing;

a laser beam source in said hand-supportable housing for producing a visible laser beam within said hand-supportable housing;

an activatable scanning mechanism in said hand-supportable housing for repeatedly scanning, when activated, said visible laser beam through said light transmission aperture, and across said scan field and a bar code symbol on said detected object;

light detection means in said hand-supportable housing, for detecting the intensity of laser light reflected off said bar code symbol as said visible laser beam is repeatedly scanned across said scan field and said bar code symbol, and for automatically producing scan data indicative of the detected intensity of said reflected laser light;

scan data processing means in said hand-supportable housing, for processing produced scan data so as to detect and decode said bar code symbol on said detected object, and upon, detecting and decoding said bar code symbol on said detected object, automatically producing symbol character data representative of said decoded bar code symbol;

manually actuatable means for generating a read-repeat signal representative of a request by the user of said automatically bar code symbol reading system to produce once again symbol character data representative of said decoded bar code symbol; and

system control means for controlling the operation of said automatic bar code reading system, said system control means including

first control means for controlling the operation of said object detection means,

second control means for automatically activating said activatable scanning mechanism for up to a first predetermined time period in response to the generation of said activation signal, and

third control means for automatically continuing the activation of said activatable scanning mechanism for up to a second predetermined time period in response to said scan data processing means detecting and decoding said bar code symbol on said detected object within said first predetermined time period, thereby permitting the detection and decoding of another bar code symbol in said scan field.

36. An automatic bar code symbol reading system, comprising:

a hand-supportable housing having a light transmission aperture through which visible light can exit and enter said hand-supportable housing;

an object detection means in said hand-supportable housing automatically generating an activation signal in response to the detection of an object located within at least a portion of a scan field defined external to said hand-supportable housing;

a laser beam source in said hand-supportable housing for producing a visible laser beam within said hand-supportable housing;

an activatable scanning mechanism in said hand-supportable housing for repeatedly scanning, when activated, said visible laser beam through said light transmission aperture, and across said scan field and a bar code symbol on said detected object;

light detection means in said hand-supportable housing, for detecting the intensity of laser light reflected off said bar code symbol as said visible laser beam is repeatedly scanned across said scan field and said bar code symbol, and for automatically producing scan data indicative of the detected intensity of said reflected laser light;

scan data processing means in said hand-supportable housing, for processing produced scan data so as to detect and decode said bar code symbol on said detected object, and upon detecting and decoding said bar code symbol on said detected object, automatically producing symbol character data representative of said decoded bar code symbol;

manually actuatable means for generating a read-repeat signal representative of a request by the user of said automatically bar code symbol reading system to detect and decode once again said decoded bar code symbol; and

system control means for controlling the operation of said automatic bar code reading system, said system control means including

first control means for controlling the operation of said object detection means,

second control means for automatically activating said activatable scanning mechanism for up to a first predetermined time period in response to the generation of said activation signal, and

third control means for automatically continuing the activation of said activatable scanning mechanism for up to a second predetermined time period in response to said scan data processing means detecting and decoding said bar code symbol on said detected object within said first predetermined time period, thereby permitting the detection and decoding of another bar code symbol in said scan field.

37. An automatic bar code symbol reading system, comprising:

a hand-supportable housing having a light transmission aperture through which visible light can exit and enter said hand-supportable housing;

an object detection means in said hand-supportable housing automatically generating an activation signal in response to the detection of an object located within at least a portion of a scan field defined external to said hand-supportable housing;

a laser beam source in said hand-supportable housing for producing a visible laser beam within said hand-supportable housing;

an activatable scanning mechanism in said hand-supportable housing for repeatedly scanning, when activated, said visible laser beam through said light transmission aperture, and across said scan field and a bar code symbol on said detected object;

light detection means in said hand-supportable housing, for detecting the intensity of laser light reflected off said bar code symbol as said visible laser beam is repeatedly scanned across said scan field and said bar code symbol, and for automatically producing scan data indicative of the detected intensity of said reflected laser light;

activatable scan data processing means in said hand-supportable housing for processing, when activated, produced scan data so as to detect and decode said bar code symbol on said detected object, and upon detecting and decoding said bar code symbol on said detected object, automatically producing symbol character data representative of said decoded bar code symbol;

manually actuatable means for generating a read-repeat signal representative of a request by the user of said automatically bar code symbol reading system, to produce once again symbol character data representative of said decoded bar code symbol; and

system control means for automatically controlling the operation of said activatable scanning mechanism and said activatable scan data processing means using said activation signal and said read-repeat signal, so as to permit the sequential detection and decoding of two or more bar code symbols in said scan field.

38. An automatic bar code symbol reading system, comprising:

a hand-supportable housing having a light transmission aperture through which visible light can exit and enter said hand-supportable housing;

an object detection means in said hand-supportable housing automatically generating an activation signal in response to the detection of an object located within at least a portion of a scan field defined external to said hand-supportable housing;

a laser beam source in said hand-supportable housing for producing a visible laser beam within said hand-supportable housing;

an activatable scanning mechanism in said hand-supportable housing for repeatedly scanning, when activated, said visible laser beam through said light transmission aperture, and across said scan field and a bar code symbol on said detected object;

light detection means in said hand-supportable housing, for detecting the intensity of laser light reflected off said bar code symbol as said visible laser beam is repeatedly scanned across said scan field and said bar code symbol, and for automatically producing scan data indicative of the detected intensity of said reflected laser light;

activatable scan data processing means in said hand-supportable housing for processing, when activated, produced scan data so as to detect and decode said bar code symbol on said detected object, and upon detecting and decoding said bar code symbol on said detected object, automatically producing symbol character data representative of said decoded bar code symbol;

manually actuatable means for generating a read-repeat signal representative of a request by the user of said automatically bar code symbol reading system to detect and decode once again symbol character data representative of said decoded bar code symbol; and

system control means for automatically controlling the operation of said activatable scanning mechanism and said activatable scan data processing means using said activation signal and said read-repeat signal, so as to permit the sequential detection and decoding of two or more bar code symbols in said scan field.

39. An automatic bar code symbol reading system comprising:

a hand-supportable housing having a light transmission aperture through which visible light can exit and enter said hand-supportable housing;

an object detection circuit in said hand-supportable unit, for automatically generating a first signal in response to the detection of an object located in a scan field defined external to said hand-supportable housing;

a laser beam source in said hand-supportable housing for producing a visible laser beam;

an activatable scanning mechanism is said hand-supportable housing for repeatedly scanning, when activated, said visible laser beam through said light transmission aperture, and across said scan field and a first bar code symbol on said detected object;

light detection means in said hand-supportable housing, for detecting the intensity of laser light reflected off said first bar code symbol as said visible light beam is repeatedly scanned across said scan field and said first bar code symbol on said detected object, and for automatically producing scan data indicative of the detected intensity of said reflected laser light;

scan data processing means for processing produced scan data in order to detect and decode said first bar code symbol on said detected object, and upon detecting and decoding said first bar code symbol character data representative of said decoded bar code symbol;

means for generating a second signal representative of a request by the user of said automatically bar code symbol reading system, to produce once again symbol character data representative of said decoded bar code symbol; and

control means for controlling the operation of said automatic bar code symbol reading system using said first and second signals.

40. An automatic bar code symbol reading system comprising:

a hand-supportable housing having a light transmission aperture through which visible light can exit and enter said hand-supportable housing;

an object detection circuit in said hand-supportable unit, for automatically generating a first signal in response to the detection of an object located in a scan field defined external to said hand-supportable housing;

a laser beam source in said hand-supportable housing for producing a visible laser beam;

an activatable scanning mechanism is said hand-supportable housing for repeatedly scanning, when activated, said visible laser beam through said light transmission aperture, and across said scan field and a first bar code symbol on said detected object;

light detection means in said hand-supportable housing, for detecting the intensity of laser light reflected off said first bar code symbol as said visible light beam is repeatedly scanned across said scan field and said first bar code symbol on said detected object, and for automatically producing scan data indicative of the detected intensity of said reflected laser light;

scan data processing means for processing produced scan data in order to detect and decode said first bar code symbol on said detected object, and upon detecting and decoding said first bar code symbol character data representative of said decoded bar code symbol;

means for generating a second signal representative of a request by the user of said automatically bar code symbol reading system, to detect and decode once again said decoded bar code symbol; and

control means for controlling the operation of said automatic bar code symbol reading system using said first and second signals.