EP0444962A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Tone display method and apparatus therefor
Assignee: Hitachi Ltd
•
Filing: 1991-03-01
•
Granted: —
•
Expires: 2011-03-01
Abstract
Abstract In a display device of pictures, etc., an adequate brightness of pictures to be displayed is realized by varying the luminous times of the luminous elements (30; Fig. 40) constituting a display panel (3). The luminous elements receive multiple-bit codes representing levels of brightness from signals to be displayed. Time corresponding to a field of television signals is divided into a plurality of sub-field of television signals is divided into a plurality of sub-fields corresponding to the bits of a multiple-bit code. The plurality of sub-fields have lengths of time proportional to weights of the corresponding bits. The luminous elements show different levels of brightness in sub-fields corresponding to bits, having values of "1" or "0", of a multiple-bit code. For each luminous element, the time interval (Tm) from a light emission start time in a sub-field where the first light emission occurs in a time corresponding to a field till a light emission start time in a sub-field where the last light emission occurs in a time corresponding to a field is made shorter than the critical fusion period of the perception characteristic of human eyes.
Inventors
- 👤 Akihiko Hitachi Daini Kyoshinryo Kohgami
- 👤 Shigeo Mikoshiba
- 👤 Shinichi Shinada
- 👤 Mutsumi Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 19:02
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; G09G3/2007; G09G3/2018; G09G3/2022; G09G3/2033; G09G3/22; G09G3/28; G09G3/288; G09G3/298; G09G3/2983; H; H04; H04N; H04N3/00; H04N3/10; H04N3/12; H04N3/125; H04N3/127; G09G2310/00; G09G2310/02; G09G2310/0262; G09G2310/0264; G09G2310/027; G09G2310/0286; G09G2320/00; G09G2320/02; G09G2320/0209; G09G2320/0247; G09G2320/0266; G09G3/2092; G09G5/00; G09G5/36; G09G5/39; G09G5/399; Y; Y10; Y10S; Y10S348/00; Y10S348/91
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
189 words
A method of tone display for controlling the brightness of a picture to be displayed by varying luminous times of luminous elements (30; Fig. 4) forming a display panel (3), comprising the steps of: dividing time corresponding to a field of television signals into a plurality of sub-field (b0 to b7) corresponding to bits of a multiple-bit code representing a level of brightness of each luminous element, and allotting said sub-fields to said luminous elements, said plurality of sub-fields having lengths of time proportional to weights of corresponding bits; consecutively supplying said luminous elements with said multiple-bit codes; causing said luminous elements to emit light in sub-fields corresponding to said bits, having either "1" or "0", of said multiple-bit codes, wherein for each luminous element, a time interval (Tm) from a light emission start time at a sub-field where the first light emission occurs in a time corresponding to a field till a light emission start time at a sub-field where the last light emission occurs in a time corresponding to the next field is made shorter than the critical fusion period of the perception characteristic of human eyes.
Claim 2
Dependent Claim
25 words
A method of tone display according to Claim 1, wherein said critical fusion period of the perception characteristic of human eyes is substantially 20 msec.
Claim 3
Dependent Claim
19 words
A method of tone display according to Claim 1, wherein said time interval is substantially 20.8 msec or less.
Claim 4
Dependent Claim
54 words
A method of tone display according to Claim 1, wherein at least one of said sub-fields is divided into two or more time domains arranged with at least one subfield sandwiched therebetween, thereby making it possible to cause each luminous element to emit light two or more times in a field. (Figs. 7, 8)
Claim 5
Dependent Claim
26 words
A method of tone display according to Claim 4, wherein lengths of time of said two or more time domains (b7₁, b7₂; b6₁, b6₂) are equal.
Claim 6
Dependent Claim
35 words
A method of tone display according to Claim 4, wherein at least one of said sub-fields which is divided into two or more time domains includes the most significant bit (b7) of said multiple-bit code.
Claim 7
Dependent Claim
28 words
A method of tone display according to Claim 1 wherein a plurality of sets of said sub-fields are provided in a time corresponding to a field. (Fig. 11)
Claim 8
Dependent Claim
198 words
A luminous display device comprising: a display panel (3) having arranged thereon a plurality of luminous elements (30; Fig. 4), light emission or no light emission of said luminous elements being controllable; means (2, 4 to 6) for consecutively supplying luminous elements with multiple-bit codes representing levels of brightness thereof; means (8 to 11, 13 to 20) for dividing time corresponding to a field of television signals into a plurality of sub-fields (b0 to b7) having lengths of time proportional to weights of corresponding bits of a multiple-bit code to assign said sub-fields to said luminous elements; means (8 to 11, 13 to 20) for causing said luminous elements to emit light in sub-fields corresponding to said bits, having values of either "1" or "0", of said multiple-bit codes; wherein for each luminous element, a time interval (Tm) from a light emission start time at a subfield where the first light emission occurs in a time corresponding to a field till a light emission start time at a sub-field where the last light emission occurs in a time corresponding to the next field is made shorter than the critical fusion period of the perception characteristic of human eyes.
Claim 9
Dependent Claim
24 words
A luminous display device according to Claim 8, wherein said critical fusion period of the perception characteristic of human eyes is substantially 20 msec.
Claim 10
Dependent Claim
18 words
A luminous display device according to Claim 8, wherein said time interval is substantially 20.8 msec or less.
Claim 11
Dependent Claim
54 words
A luminous display device according to Claim 8, wherein at least one of said sub-fields which is divided into two or more time domains arranged with at least one sub-field sandwiched therebetween, thereby making it possible to cause each luminous element to emit light two or more times in a field. (Figs. 7, 8)
Claim 12
Dependent Claim
25 words
A luminous display device according to Claim 11, wherein lengths of time of said two or more time domains (b7₁, b7₂; b6₁, b6₂) are equal.
Claim 13
Dependent Claim
25 words
A luminous display device according to Claim 8, wherein two sets of said sub-fields are provided in a time corresponding to a field. (Fig. 11)
Claim 14
Dependent Claim
29 words
A luminous display device according to Claim 13, wherein to one of said sets of sub-fields, interpolation signals of said multiple-bit codes in said two consecutive fields are given.
Claim 15
Dependent Claim
22 words
A luminous display device according to Claim 8, wherein said luminous elements are formed by gas discharge luminous elements having memory functions.
Claim 16
Dependent Claim
22 words
A luminous display device according to Claim 11, wherein said luminous elements are formed by gas discharge luminous elements having memory functions.
Claim 17
Dependent Claim
22 words
A luminous display device according to Claim 13, wherein said luminous elements are formed by gas discharge luminous elements having memory functions.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.