JP2002289374A - Light source, display equipment, and electronic device - Google Patents
Light source, display equipment, and electronic deviceInfo
- Publication number
- JP2002289374A JP2002289374A JP2001091432A JP2001091432A JP2002289374A JP 2002289374 A JP2002289374 A JP 2002289374A JP 2001091432 A JP2001091432 A JP 2001091432A JP 2001091432 A JP2001091432 A JP 2001091432A JP 2002289374 A JP2002289374 A JP 2002289374A
- Authority
- JP
- Japan
- Prior art keywords
- light source
- light
- capacitor
- emitting element
- capacitance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 239000003990 capacitor Substances 0.000 claims abstract description 79
- 239000004973 liquid crystal related substance Substances 0.000 claims description 8
- 238000005401 electroluminescence Methods 0.000 claims description 2
- 230000010355 oscillation Effects 0.000 description 24
- 238000010586 diagram Methods 0.000 description 14
- CNQCVBJFEGMYDW-UHFFFAOYSA-N lawrencium atom Chemical compound [Lr] CNQCVBJFEGMYDW-UHFFFAOYSA-N 0.000 description 13
- 238000000034 method Methods 0.000 description 9
- 230000003287 optical effect Effects 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000005669 field effect Effects 0.000 description 3
- WUPHOULIZUERAE-UHFFFAOYSA-N 3-(oxolan-2-yl)propanoic acid Chemical compound OC(=O)CCC1CCCO1 WUPHOULIZUERAE-UHFFFAOYSA-N 0.000 description 2
- 125000002066 L-histidyl group Chemical group [H]N1C([H])=NC(C([H])([H])[C@](C(=O)[*])([H])N([H])[H])=C1[H] 0.000 description 2
- 229910052980 cadmium sulfide Inorganic materials 0.000 description 2
- 102100036738 Guanine nucleotide-binding protein subunit alpha-11 Human genes 0.000 description 1
- 101100283445 Homo sapiens GNA11 gene Proteins 0.000 description 1
- 238000005282 brightening Methods 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/3406—Control of illumination source
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Electroluminescent Light Sources (AREA)
- Circuit Arrangement For Electric Light Sources In General (AREA)
- Liquid Crystal (AREA)
Abstract
Description
【0001】[0001]
【従来の技術】近年、表示装置として、小型軽量で低消
費電力といった特徴を持つ液晶表示装置が広く用いられ
ている。しかし、陰極線管(CRT)等の自発光型表示装置
と異なり、液晶素子自体は発光しないので暗い所でも液
晶表示装置を機能させるには光源を備える必要がある。2. Description of the Related Art In recent years, liquid crystal display devices having characteristics of small size, light weight and low power consumption have been widely used as display devices. However, unlike a self-luminous display device such as a cathode ray tube (CRT), the liquid crystal element itself does not emit light, so that it is necessary to provide a light source for the liquid crystal display device to function even in a dark place.
【0002】光源として白熱電球、陰極管も用いられる
が、小型化高効率化の目的で発光ダイオード(以後、LED
と称する。)やエレクトロ・ルミネッセンス(以後、ELと称
する。)が多く使用されつつある。[0002] Incandescent lamps and cathode tubes are also used as light sources.
Called. ) And electroluminescence (hereinafter referred to as EL) are being widely used.
【0003】ここでLEDやELを定電圧駆動で発光させ
ると、これらの素子特性の僅かなばらつきや周囲温度に
よって流れる電流が大きく変わり、よって明るさが大き
く変動してしまい好ましくない。よって、一般的に定電
流駆動を行って所定の明るさの光を発光させる。図8
は、この定電流駆動を行う一回路構成例を示す図であ
る。図で101は電圧源、801は抵抗器、103はLE
DやEL等の発光素子である。抵抗器801と発光素子
103が直列に接続され、電圧源101の電圧が与えら
れる。ここで、発光素子103が、特性等のばらつきに
よって所定の値よりに大きな電流が流れようとすると、
直列に入っている抵抗器801にも大きな電流が流れそ
れによって電圧降下が生じて、発光素子103に印加す
る電圧が下がって電流の増加が抑制される。なお、抵抗
器801を可変抵抗器にすることにより、明るさを調整
することが可能になる。[0003] Here, if the LED or EL is driven to emit light by constant voltage driving, the current flowing due to a slight variation in the characteristics of these elements or the ambient temperature changes greatly, and therefore the brightness greatly changes, which is not preferable. Therefore, in general, constant current driving is performed to emit light of a predetermined brightness. FIG.
FIG. 2 is a diagram showing an example of a circuit configuration for performing the constant current driving. In the figure, 101 is a voltage source, 801 is a resistor, 103 is LE
Light emitting elements such as D and EL. The resistor 801 and the light emitting element 103 are connected in series, and the voltage of the voltage source 101 is applied. Here, if the light-emitting element 103 tries to flow a current larger than a predetermined value due to variations in characteristics and the like,
A large current also flows through the resistor 801 that is in series, which causes a voltage drop, and the voltage applied to the light emitting element 103 decreases, thereby suppressing an increase in the current. Note that the brightness can be adjusted by using the resistor 801 as a variable resistor.
【0004】ところで、PDA(Personal Digital Assista
nt)や携帯電話などのような携帯型電子機器にあっては
電池駆動が原則であり、この光源についても低消費電力
であることが要求される。また、携帯型電子機器に組み
込まれている表示装置の光源は、外光の強さ、言い換え
れば周囲の明るさに応じて光源の明るさを調光できるこ
とが好ましい。これは、周囲が明るい時には光源も明る
くすることにより視認性を上げ、暗い時は光源の明るさ
を落として、妨眩性を上げることが出来るからである。
これについては、図8の抵抗器802を可変抵抗器にす
ることにより達成することが出来る。By the way, a PDA (Personal Digital Assista)
In general, portable electronic devices such as nt) and mobile phones are driven by batteries, and this light source is also required to have low power consumption. Further, it is preferable that the light source of the display device incorporated in the portable electronic device can adjust the brightness of the light source according to the intensity of external light, in other words, the surrounding brightness. This is because when the surroundings are bright, the visibility can be increased by brightening the light source, and when dark, the brightness of the light source can be reduced to increase the antiglare property.
This can be achieved by making the resistor 802 in FIG. 8 a variable resistor.
【0005】[0005]
【発明が解決しようとする課題】しかしながら、従来の
LEDやELの定電流駆動では、定電流化する為の抵抗器
に電流が流れてこの部分で発光に関与しない無駄な電力
が消費されるという課題がある。SUMMARY OF THE INVENTION However, the conventional
In the constant current driving of the LED or the EL, there is a problem that a current flows through a resistor for making the current constant, and wasteful power not involved in light emission is consumed in this portion.
【0006】本発明は、上述した事情を鑑みてなされた
もので、その目的とするところは、光源の高効率化を図
り、容易な調光をすることが可能な光源及び電子機器を
提供することにある。SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a light source and an electronic device capable of improving the efficiency of a light source and performing dimming easily. It is in.
【0007】[0007]
【課題を解決するための手段】上記目的を達成するため
に、第1の本発明の光源は、コンデンサと、電源と、発
光素子と、前記コンデンサを前記電源又は前記発光素子
のいずれかと交互に接続させる第1のスイッチ素子を具
備することを特徴とする。In order to achieve the above object, a light source according to a first aspect of the present invention comprises a capacitor, a power supply, a light emitting element, and the capacitor alternately connected to either the power supply or the light emitting element. A first switch element to be connected is provided.
【0008】この構成によれば、電源電圧をV、コンデ
ンサ容量をC、第1のスイッチ素子の切替周期をTとす
ると、まずコンデンサは電源と接続して電荷CVを充電
する。次にコンデンサは発光素子と接続して電荷CVを
発光素子に供給する。これが1秒間に1/T回繰り返さ
れるので、CV/Tの定電流が発光素子に流れることに
なる。この時、従来技術の抵抗器が存在しないので無駄
な消費電力が発生しない。According to this configuration, assuming that the power supply voltage is V, the capacitance of the capacitor is C, and the switching period of the first switch element is T, the capacitor is first connected to the power supply and charges the electric charge CV. Next, the capacitor is connected to the light emitting element and supplies the charge CV to the light emitting element. Since this is repeated 1 / T times per second, a constant current of CV / T flows through the light emitting element. At this time, there is no useless power consumption because there is no prior art resistor.
【0009】また第2の本発明の光源は、複数のコンデ
ンサと、電源と、発光素子と、前記複数のコンデンサを
前記電源と並列に接続する状態と前記複数のコンデンサ
を直列接続して前記発光素子と接続する状態のいずれか
に交互に切り替える第2のスイッチ素子を具備すること
を特徴とする。A light source according to a second aspect of the present invention includes a plurality of capacitors, a power supply, a light emitting element, a state in which the plurality of capacitors are connected in parallel with the power supply, and a method in which the plurality of capacitors are connected in series. A second switch element for alternately switching to one of a state of connection with the element.
【0010】この構成によれば、例えば2つのコンデン
サがまずそれぞれ電源と並列に接続し、電圧V(電荷C
V)まで充電する。その後、コンデンサは直列接続され
てその両端の電圧は2Vとなる。この電圧で発光素子を
駆動する。これにより、発光素子の駆動に必要な最低電
圧よりも低い電源でも発光素子を駆動できる。ここでは
2つのコンデンサで説明したが任意の個数nで並直切替
すると電圧nVの電圧となる。According to this configuration, for example, two capacitors are first connected in parallel with the power supply, respectively, and the voltage V (charge C)
V). Thereafter, the capacitors are connected in series, and the voltage across both ends becomes 2V. The light emitting element is driven by this voltage. Thus, the light emitting element can be driven with a power supply lower than the minimum voltage required for driving the light emitting element. Here, the description has been made with two capacitors, but if the switching is performed in parallel with an arbitrary number n, the voltage becomes nV.
【0011】また本発明の他の光源は、第1乃至2の光
源において、前記第1または第2のスイッチ素子が前記
コンデンサを前記電源又は前記発光素子のいずれかと交
互に接続させる切替周期を可変させる周期可変手段を具
備することを特徴とする。According to another aspect of the present invention, in the first or second light source, the first or second switch element varies a switching cycle for alternately connecting the capacitor to either the power supply or the light emitting element. It is characterized in that it comprises a period changing means for performing the operation.
【0012】この構成によれば、発光素子に流れる電流
(CV/T)を、切替周期Tを可変することにより、発光
素子の明るさを調節できるようになる。なお切替周期を
可変する方法として手動で行う方法があり、利用者が好
みに応じて手動で可変することが可能で好みの明るさに
することが可能である。また、透過型の液晶表示装置の
バックライトに用いる場合には、外光が強いほど光源の
明るさを強くすることによって見やすくなる。そこで、
外光が強くなった場合に自動的に切替周期を短くするこ
とにより最適な明るさにすることが可能となる。無論、
手動と外光の強度の両方によって切替周期を調整するこ
とで最適な明るさにすることが可能である。According to this configuration, the current flowing through the light emitting element
By changing the switching period T of (CV / T), the brightness of the light emitting element can be adjusted. As a method of changing the switching period, there is a method of manually changing the switching period, and the user can manually change the switching period according to his / her preference, and can achieve a desired brightness. In addition, when used for a backlight of a transmissive liquid crystal display device, the external light becomes more intense by increasing the brightness of the light source as the external light becomes stronger. Therefore,
By automatically shortening the switching period when the external light becomes strong, it is possible to obtain the optimum brightness. Of course,
By adjusting the switching period both manually and by the intensity of the external light, it is possible to obtain the optimum brightness.
【0013】更に本発明の他の光源は、第1乃至2の光
源において、前記コンデンサまたは前記複数のコンデン
サの容量を変化させる容量可変手段を具備することを特
徴とする。Further, another light source according to the present invention is characterized in that, in the first and second light sources, a capacitance changing means for changing a capacitance of the capacitor or the plurality of capacitors is provided.
【0014】この構成によれば、発光素子に流れる電流
(CV/T)を、コンデンサの容量のCを可変することに
より、発光素子の明るさを調節できるようになる。なお
コンデンサの容量を可変する方法として手動で行う方法
があり、利用者が好みに応じて手動で可変することが可
能で好みの明るさにすることが可能である。また、外光
が強くなった場合に自動的にコンデンサの容量を大きく
することにより最適な明るさにすることが可能となる。
無論、手動と外光の強度の両方によってコンデンサの容
量を調整することで最適な明るさにすることが可能であ
る。According to this configuration, the current flowing through the light emitting element
By changing (CV / T) the capacitance C of the capacitor, the brightness of the light emitting element can be adjusted. Note that there is a method of manually changing the capacitance of the capacitor, and the user can manually change the capacitance according to his / her preference, and can achieve a desired brightness. In addition, when external light becomes strong, the capacity of the capacitor is automatically increased, so that optimum brightness can be obtained.
Of course, it is possible to obtain the optimum brightness by adjusting the capacitance of the capacitor both manually and by the intensity of the external light.
【0015】そして、明るさ調整として、切替周期とコ
ンデンサ容量の両方を可変にすること、その可変方法と
して手動、外光に応じたものの一方あるいは両方にする
ことにより、最適な明るさの調整範囲を広げあるいは細
かくすることが可能である。The brightness can be adjusted by changing both the switching period and the capacitance of the capacitor, and the variable method can be adjusted manually or in accordance with external light, or both, to obtain the optimum brightness adjustment range. Can be expanded or fined.
【0016】本発明の光源に用いる発光素子として白熱
電球、陰極管、EL、LED等の多くの種類が適する
が、低電圧、小型、軽量、耐久性、高効率といった面か
ら、特にEL、LEDが好ましい。Many types of light emitting elements used for the light source of the present invention, such as incandescent lamps, cathode tubes, ELs, and LEDs, are suitable. Is preferred.
【0017】本発明の電子機器は、上述した光源を備え
るので、低消費電力化及び構成の簡素化がなされる。な
お、光源が表示装置の光源として用いられ、この表示装
置が上位の電子機器に組み込むことが可能で、表示装置
とひいては上位の電子機器の低消費電力化及び構成の簡
素化がなされる。Since the electronic apparatus of the present invention includes the above-described light source, power consumption is reduced and the configuration is simplified. Note that the light source is used as a light source of the display device, and this display device can be incorporated in a higher-order electronic device, so that the power consumption of the display device and, consequently, the higher-order electronic device can be reduced and the configuration can be simplified.
【0018】このような電子機器として、パーソナル・
コンピュータ、携帯電話、デジタル・スチル・カメラ等々
が挙げられる。As such an electronic device, a personal computer
Computers, mobile phones, digital still cameras, and the like.
【0019】[0019]
【発明の実施の形態】以下、本発明の実施の形態につい
て図面を参照して説明する。Embodiments of the present invention will be described below with reference to the drawings.
【0020】[第1の実施形態] <構成>初めに、本発明の第1の実施形態に係る光源の
電気的構成について説明する。図1は、この電気的回路
構成を示す図である。図で、101は電源、102はス
イッチ回路、103は発光素子、104はコンデンサ、
105はロジック発振回路である。電源101は電圧V
を出力する。スイッチ回路102は、端子a、b、c、
sを持ち、端子aは電源101の一端と、端子bは発光
素子の一端と、端子cはコンデンサ104の一端と接続
されている。電源101、コンデンサ104、発光素子
103の他端は共通電位に接地されている。(図中、▽
記号) スイッチ回路102の端子sは入力端子で、ロジ
ック発振回路105の出力信号を入力する。なお、ロジ
ック発振回路105は2値のクロック信号を出力する。
ここで、2値の内一方の値をLとし他方の値をHとし
て、Lの信号の時、スイッチ回路102は端子aとcを
導通させ、Hの時に端子cとbを導通させる。発光素子
103として白熱電球、陰極管、EL、LED等の多く
の種類の発光素子が適用できるが、低電圧、小型、軽
量、耐久性、高効率といった面から、特にEL、LED
が好ましい。ここではLEDを用いる。ここで、スイッ
チ回路102の具体的な一構成例を図2に示す。図で、
端子a、b、c、sは図1のスイッチ回路102の各端
子に対応する。図2の201はPchの電界効果トラン
ジスタ(以後、FETと称する。)、202はNchの
FETである。端子aはFET201のソース、端子b
はFET202のソース、端子cはFET201と20
2の両方のドレインと接続されている。そして、端子s
はFET201と202の両方のゲートと接続されてい
る。よって、端子sの電位が端子aよりも低くなり端子
bの電位近く以下になると、FET201は導通し、F
ET202は不導通となる。逆に、端子sの電位が端子
bよりも高くなり端子aの電位近く以上になると、FE
T202は導通し、FET201は不導通となる。First Embodiment <Structure> First, the electrical structure of a light source according to a first embodiment of the present invention will be described. FIG. 1 is a diagram showing this electric circuit configuration. In the figure, 101 is a power supply, 102 is a switch circuit, 103 is a light emitting element, 104 is a capacitor,
105 is a logic oscillation circuit. Power supply 101 has voltage V
Is output. The switch circuit 102 has terminals a, b, c,
The terminal a is connected to one end of the power supply 101, the terminal b is connected to one end of the light emitting element, and the terminal c is connected to one end of the capacitor 104. The other ends of the power supply 101, the capacitor 104, and the light emitting element 103 are grounded to a common potential. (In the figure, ▽
Symbol) The terminal s of the switch circuit 102 is an input terminal to which an output signal of the logic oscillation circuit 105 is input. Note that the logic oscillation circuit 105 outputs a binary clock signal.
Here, when one of the two values is L and the other value is H, the switch circuit 102 conducts the terminals a and c when the signal is L, and conducts the terminals c and b when the signal is H. As the light emitting element 103, many types of light emitting elements such as an incandescent light bulb, a cathode ray tube, an EL, and an LED can be applied. However, from the viewpoints of low voltage, small size, light weight, durability, and high efficiency, EL and LED are particularly preferable.
Is preferred. Here, an LED is used. Here, a specific configuration example of the switch circuit 102 is shown in FIG. In the figure,
The terminals a, b, c, and s correspond to the respective terminals of the switch circuit 102 in FIG. In FIG. 2, reference numeral 201 denotes a Pch field effect transistor (hereinafter, referred to as an FET), and reference numeral 202 denotes an Nch FET. Terminal a is the source of FET 201, terminal b
Is the source of the FET 202, and the terminal c is the FETs 201 and 20.
2 are connected to both drains. And the terminal s
Is connected to both gates of the FETs 201 and 202. Therefore, when the potential of the terminal s becomes lower than the potential of the terminal a and becomes lower than the potential of the terminal b or less, the FET 201 conducts, and F
The ET 202 becomes non-conductive. Conversely, when the potential of the terminal s becomes higher than the potential of the terminal b and becomes equal to or higher than the potential of the terminal a, FE
T202 becomes conductive and FET 201 becomes nonconductive.
【0021】次に、図1の発振回路105の具体的な一
構成例を図3に示す。図で、301はシュミットトリガ
型ロジック反転回路、302は容量Coscを持つコンデ
ンサ、303は抵抗値Roscを持つ抵抗器である。ここ
で、コンデンサの一端はある電位に接地され、他端はロ
ジック反転回路301の入力aに接続されている。抵抗
器303の一端はロジック反転回路301の入力aに接
続されて、他端はロジック反転回路301の出力Yに接
続されている。このような構成となっており、Roscと
Coscの積にほぼ比例した周期のクロック信号を出力す
る。この時の発振周波数f「Hz」は周期をTとした時にf
=1/Tで表される。Next, FIG. 3 shows a specific configuration example of the oscillation circuit 105 of FIG. In the figure, 301 is a Schmitt trigger type logic inversion circuit, 302 is a capacitor having a capacitance Cosc, and 303 is a resistor having a resistance value Rosc. Here, one end of the capacitor is grounded to a certain potential, and the other end is connected to the input a of the logic inversion circuit 301. One end of the resistor 303 is connected to the input a of the logic inversion circuit 301, and the other end is connected to the output Y of the logic inversion circuit 301. With such a configuration, a clock signal having a cycle substantially proportional to the product of Rosc and Cosc is output. The oscillation frequency f “Hz” at this time is f
= 1 / T.
【0022】第1の実施形態の光源は以上の構成となっ
ている。The light source of the first embodiment has the above configuration.
【0023】<動作>次に動作を説明する。まず、図1
の発振回路105の出力がLの状態の時、スイッチ回路
102は端子aとcを導通させるので、電源101の電
圧Vでコンデンサ104を充電する。即ち、コンデンサ
104に電荷CVが蓄えられる。なお、端子aとcを導
通させる期間は、充分にコンデンサ104に電荷が蓄え
られる期間である必要がある。逆に言うと、コンデンサ
104の容量値は、端子aとcが導通している期間内
に、充分電荷をチャージできる値である必要がある。<Operation> Next, the operation will be described. First, FIG.
When the output of the oscillation circuit 105 is in the L state, the switch circuit 102 conducts the terminals a and c, so that the capacitor 104 is charged with the voltage V of the power supply 101. That is, the charge CV is stored in the capacitor 104. Note that the period during which the terminals a and c are conducted needs to be a period during which charges are sufficiently stored in the capacitor 104. Conversely, the capacitance value of the capacitor 104 needs to be a value that can sufficiently charge the electric charge during the period when the terminals a and c are conducting.
【0024】次に発振回路104の出力がHの状態にな
ると、スイッチ回路102は端子bとcを導通させるの
で、コンデンサ104は電荷CVを発光素子103に放
出する。即ち発光素子103に電流が流れる。ここで、
発光素子が白熱電球等の場合には印加する電圧が0にな
るまで電流が流れ続けるが、LEDの場合にはある印加
電圧(電圧VFとする)以下になると電流が流れなくな
る。従って、コンデンサ104が放出する電荷量はC
(V−VF)となる。端子bとcを導通させる期間は、
コンデンサ104に貯まっていた電荷が充分に放出され
るだけの期間である必要がある。逆に言うと、コンデン
サ104の容量値、発光素子103の抵抗値は、端子b
とcが導通している期間内に、コンデンサから電荷を充
分放出できる値である必要がある。Next, when the output of the oscillation circuit 104 becomes H level, the switch circuit 102 conducts the terminals b and c, so that the capacitor 104 discharges the electric charge CV to the light emitting element 103. That is, current flows through the light emitting element 103. here,
When the light emitting element is an incandescent light bulb or the like, the current continues to flow until the applied voltage becomes 0. However, when the light emitting element is an LED, the current stops flowing when the applied voltage becomes lower than a certain applied voltage (voltage VF). Therefore, the amount of charge released by the capacitor 104 is C
(V-VF). The period for conducting the terminals b and c is
It is necessary that the period be such that the charges stored in the capacitor 104 are sufficiently released. Conversely, the capacitance value of the capacitor 104 and the resistance value of the light emitting element 103 are determined by the terminal b
It is necessary for the capacitor to have a value that can sufficiently release the electric charge from the capacitor during the period when and c are conducting.
【0025】これが1秒間にf回繰り返されるので、平
均電流はC(V−VF)fとなる。ここで、消費される
電力は発光素子103のみであり、無駄な電力消費が無
くなる。なお、ロジック発振回路104の発振周波数f
はあまり低いとフリッカが生じるので低くとも30Hz
以上が好ましく、より好ましくは50Hz以上に設定す
る。 なお、ここで説明した、スイッチ回路102及び
発振回路105の具体的な構成例は本発明を具現化する
のを容易にするものであり、この構成に限定するもので
はなく、本明細書の趣旨に合えばいかなる構成でも構わ
ない。Since this is repeated f times in one second, the average current becomes C (V-VF) f. Here, the consumed power is only the light emitting element 103, and unnecessary power consumption is eliminated. Note that the oscillation frequency f of the logic oscillation circuit 104
Is too low, flicker occurs, so at least 30Hz
Preferably, the frequency is set to 50 Hz or more. Note that the specific configuration examples of the switch circuit 102 and the oscillation circuit 105 described herein facilitate embodying the present invention, and the present invention is not limited to this configuration. Any configuration is acceptable as long as it is suitable.
【0026】[第2の実施形態] <構成>第1の実施形態で説明したように、発光素子に
流れる平均電流はC(V−VF)fで規定され、周波数
fに比例する。よって、スイッチ回路102の切替周波
数fを変更することによって、発光素子に流れる平均電
流を調節でき、調光可能となる。ここでこれを図で説明
する。図4は本発明の第2の実施形態に係る光源の電気
的構成を示す図である。図で405以外は、図1と同じ
構成と動作をするので同じ番号を付して説明の重複を避
ける。405はクロック信号の周波数を可変できるよう
にした発振回路である。図5はロジック発振回路405
の具体的な一構成例を示す図である。図5で501以外
は図3のロジック発振回路105と同じ構成と動作をす
るので同じ番号を付して説明を省略する。501は可変
抵抗器で、反転回路301の入力と出力の間に抵抗器3
03と直列接続するように挿入されている。[Second Embodiment] <Configuration> As described in the first embodiment, the average current flowing through the light emitting element is defined by C (V-VF) f, and is proportional to the frequency f. Therefore, by changing the switching frequency f of the switch circuit 102, the average current flowing through the light emitting element can be adjusted, and light can be adjusted. This will now be described with reference to the drawings. FIG. 4 is a diagram showing an electrical configuration of a light source according to the second embodiment of the present invention. In the figure, components other than 405 have the same configuration and operation as those in FIG. Reference numeral 405 denotes an oscillation circuit that can change the frequency of the clock signal. FIG. 5 shows a logic oscillation circuit 405.
FIG. 3 is a diagram showing a specific example of the configuration of FIG. In FIG. 5, components other than 501 have the same configuration and operation as the logic oscillation circuit 105 of FIG. Reference numeral 501 denotes a variable resistor, and a resistor 3 is provided between the input and output of the inverting circuit 301.
03 to be connected in series.
【0027】<動作>以上の構成となっているので、例
えば手動で図5の可変抵抗器501の抵抗値を変更する
ことよって図4の発振回路405の発振周波数は変化
し、それに従い発光素子103に流れる平均電流が変化
し、最適な明るさに調光することが出来る。<Operation> With the above configuration, the oscillation frequency of the oscillation circuit 405 in FIG. 4 is changed by, for example, manually changing the resistance value of the variable resistor 501 in FIG. The average current flowing through 103 changes, and light can be adjusted to an optimal brightness.
【0028】ここで、必要に応じて可変抵抗器501ま
たは反転回路301の入力と出力間に並列に固定抵抗器
を付加しても良い。これにより調光範囲や調光のしやす
さを適正にすることが出来る。Here, if necessary, a fixed resistor may be added in parallel between the input and output of the variable resistor 501 or the inverting circuit 301. Thereby, the light control range and the ease of light control can be made appropriate.
【0029】以上のように、発振周波数を変えるだけ、
言い換えれば可変抵抗器を付加させるだけで容易に調光
が可能であり、第1の実施形態同様に高効率化が図れ
る。As described above, just by changing the oscillation frequency,
In other words, dimming can be easily performed only by adding a variable resistor, and high efficiency can be achieved as in the first embodiment.
【0030】[第3の実施形態]なお、第2の実施形態の
光源において、図5の可変抵抗器501の代わりに、周
囲の明るさ即ち外光の強さによって抵抗値の変化する光
センサ素子を用いることが出来る。そのような素子とし
て、硫化カドニウム(CdS)セル等の光伝導素子があ
る。この素子は、この素子にあたる光が強くなると、そ
の抵抗値が小さくなる性質を持っている。よって、外光
の強さが強くなると抵抗値が低くなるので、発振回路5
01の発振周波数fは外光が強くなるほど高くなって発
光素子はより明るくなり、外光が弱い時には発光素子は
暗くなり、最適な明るさに自動的に調整される。[Third Embodiment] In the light source according to the second embodiment, instead of the variable resistor 501 shown in FIG. 5, an optical sensor whose resistance value changes according to ambient brightness, that is, the intensity of external light. An element can be used. Such devices include photoconductive devices such as cadmium sulfide (CdS) cells. This element has such a property that the resistance value decreases when light hitting the element increases. Therefore, when the intensity of external light increases, the resistance value decreases.
The oscillation frequency f of 01 becomes higher as the external light becomes stronger, and the light emitting element becomes brighter. When the external light is weak, the light emitting element becomes darker, and is automatically adjusted to the optimal brightness.
【0031】[第4の実施形態]また、第2の実施形態の
光源において、図5の可変抵抗器501に光センサ素子
を直列もしくは並列に接続することが出来る。これによ
り、手動の調光と外光による自動調光が可能となりより
最適な明るさに調光することが可能となる。[Fourth Embodiment] In the light source of the second embodiment, an optical sensor element can be connected in series or in parallel to the variable resistor 501 shown in FIG. As a result, manual light control and automatic light control using external light can be performed, and light control can be performed to more optimal brightness.
【0032】本実施形態でも、反転回路301の入力と
出力間に介在する固定抵抗器303、可変抵抗器50
1、光センサ素子の任意の間に並列に固定抵抗器を付加
しても良い。これにより調光範囲や自動調整を含む調光
のしやすさを適正にすることが出来る。 [第5の実施形態]第1の実施形態で説明したように、発
光素子103に流れる平均電流はC(V−VF)fとな
る。従って、図1のコンデンサ104の容量Cを変化さ
せても、発光素子103に流れる平均電流が変化し明る
さが変わる。従って、調光可能である。Also in this embodiment, the fixed resistor 303 and the variable resistor 50 interposed between the input and output of the inverting circuit 301 are used.
1. A fixed resistor may be added in parallel between any of the optical sensor elements. This makes it possible to properly adjust the light control range including the light control range and the automatic adjustment. [Fifth Embodiment] As described in the first embodiment, the average current flowing through the light emitting element 103 is C (V-VF) f. Therefore, even if the capacitance C of the capacitor 104 in FIG. 1 is changed, the average current flowing through the light emitting element 103 changes and the brightness changes. Therefore, dimming is possible.
【0033】<構成>図6は、第5の実施形態の光源の
電気的回路構成を示す図である。図で6041、604
2、6061、6062以外の構成と動作は図1と同じ
で同じ番号を付して説明を省略する。6041と604
2はそれぞれc1、c2の容量を持つコンデンサで、6
061と6062はスイッチ回路で、それぞれコンデン
サ6041と6042をある電位と接続または遮断する
スイッチである。<Structure> FIG. 6 is a diagram showing an electric circuit structure of the light source according to the fifth embodiment. In the figure, 6041 and 604
Components and operations other than 2, 6061 and 6062 are the same as those in FIG. 6041 and 604
2 is a capacitor having a capacity of c1 and c2, respectively.
Reference numerals 061 and 6062 denote switch circuits for connecting or disconnecting the capacitors 6041 and 6042 with a certain potential, respectively.
【0034】<動作>以上の構成となっているので、ス
イッチ回路6061が導通、6062が遮断状態(これ
を状態1とする。)にすると、発光素子に流れる平均電
流は、c1(V−VF)fとなる。次にスイッチ回路6
061が遮断、6062が導通状態にすると、発光素子
に流れる平均電流は、c2(V−VF)fとなる。そし
て、スイッチ回路6061と6062を共に導通状態に
すると、発光素子に流れる平均電流は、(c1+c2)
(V−VF)fとなる。従って、c1とc2を異なった
容量にすることにより、3段階の調光が可能となる。特
に、c2=2c1となるようにコンデンサの容量を設定
すると、平均電流は、状態1の平均電流を1とした場合
に1倍、2倍,3倍と等間隔に設定することが可能であ
る。<Operation> With the above configuration, when the switch circuit 6061 is turned on and the switch circuit 6062 is turned off (this state is referred to as state 1), the average current flowing through the light emitting element is c1 (V-VF). ) f. Next, switch circuit 6
When 061 is turned off and 6062 is turned on, the average current flowing through the light emitting element is c2 (V-VF) f. When the switch circuits 6061 and 6062 are both turned on, the average current flowing through the light emitting element is (c1 + c2).
(V-VF) f. Therefore, by setting c1 and c2 to have different capacities, light control in three stages can be performed. In particular, when the capacitance of the capacitor is set so that c2 = 2c1, the average current can be set to be equal to 1, 2, or 3 times as long as the average current in state 1 is 1. .
【0035】なお、本実施形態ではコンデンサ604
1、6042の両方にスイッチ回路6061、6062
が挿入されているが、一方は常に接地しておいても良
い。In this embodiment, the capacitor 604
1 and 6042, switch circuits 6061 and 6062
Are inserted, but one may be always grounded.
【0036】また、本実施形態では、コンデンサ及びこ
れに対応するコンデンサの数を2つとしてあるが、これ
に限定するものではなく、3つ以上でも無論構わない。
そして、これらのコンデンサの各容量は任意でも良い
が、最小容量の2倍、4倍、8倍と2のべき乗にし、適
宜接地するコンデンサを選択することにより平均電流を
等間隔に設定することが可能となる。Further, in this embodiment, the number of capacitors and the number of capacitors corresponding thereto are two, but the number is not limited to this, and three or more capacitors may be used.
The capacity of each of these capacitors may be arbitrarily set, but it is possible to set the average current at equal intervals by selecting a capacitor which is twice, four times, eight times and a power of 2 and the grounding is appropriately performed. It becomes possible.
【0037】[第6の実施形態]第5の実施形態におい
て、スイッチ回路6061、6062のオン/オフ制御
を外光によって制御しても良い。即ち、外光の強度を任
意の光センサで感知しこれをアナログ−デジタル変換回
路でデジタル量に変換し、各bitの状態によりスイッ
チ回路6061、6062のオン/オフ制御させても良
い。これにより、第3の実施形態と同様の効果が得られ
る。[Sixth Embodiment] In the fifth embodiment, the on / off control of the switch circuits 6061 and 6062 may be controlled by external light. That is, the intensity of the external light may be sensed by an arbitrary optical sensor, converted into a digital amount by an analog-to-digital converter, and the ON / OFF control of the switch circuits 6061 and 6062 may be performed according to the state of each bit. Thereby, the same effect as in the third embodiment can be obtained.
【0038】[第7の実施形態]第5の実施形態におい
て、スイッチ回路6061のオン/オフ制御を第6の実
施形態の如く外光によって制御し、スイッチ回路606
2のオン/オフ制御を手動にしても良い。これにより、
第4の実施形態と同様の効果が得られる。無論、本実施
形態においてもコンデンサの個数及び容量は任意であっ
て構わない。[Seventh Embodiment] In the fifth embodiment, the on / off control of the switch circuit 6061 is controlled by external light as in the sixth embodiment.
2 may be manually controlled. This allows
The same effects as in the fourth embodiment can be obtained. Of course, the number and capacity of the capacitors may be arbitrary in the present embodiment.
【0039】[第8の実施形態]第2ないし4の実施形態
で、スイッチ回路102の切替周期を可変することによ
り調光する方法を述べ、第5ないし7の実施形態でコン
デンサの容量を可変することにより調光する方法を述べ
た。ここで、スイッチ回路102の切替周期を可変しか
つコンデンサの容量を可変する構成でも構わない。この
構成については、上述の実施形態を単に複合させたもの
であり容易に具現化できるので詳細な説明は行わない
が、例えば大雑把な調光はコンデンサの容量を可変する
方法を用い、細かな調光は切替周期を可変する方法を用
いることにより広範囲にきめ細かい調光が可能になる。
そして、必要に応じて一部を手動で一部を外光に応じた
調光にしても良く、これも容易に具現化できる。[Eighth Embodiment] In the second to fourth embodiments, the method of dimming by changing the switching period of the switch circuit 102 will be described. In the fifth to seventh embodiments, the capacitance of the capacitor will be changed. The dimming method was described by doing so. Here, a configuration in which the switching cycle of the switch circuit 102 is varied and the capacitance of the capacitor is varied may be used. This configuration will not be described in detail because it is a simple combination of the above embodiments and can be easily embodied. For example, rough dimming is performed by using a method of varying the capacitance of a capacitor. Light can be finely adjusted over a wide range by using a method of changing the switching cycle.
If necessary, a part of the light may be manually adjusted to adjust the light in accordance with the external light, and this can be easily realized.
【0040】[第9の実施形態]第1の実施形態で発光
素子としてLEDを用いた例を示したが、電源101と
して低電圧Vの電池等で、LEDのVFに対してV<V
Fの場合にはLEDには電流が流れず光源として機能し
ない。本実施形態ではこのように発光素子に必要な最低
電圧以下の電源電圧でも機能する光源の電気的構成を示
す。[Ninth Embodiment] In the first embodiment, an example is shown in which an LED is used as a light emitting element. However, a low voltage V battery or the like is used as the power supply 101, and V <V with respect to the LED VF.
In the case of F, no current flows through the LED and the LED does not function as a light source. In this embodiment, an electrical configuration of a light source that functions even with a power supply voltage equal to or lower than the minimum voltage necessary for the light emitting element is described.
【0041】<構成>図7は本実施形態の光源の電気的
構成を示す図である。図で電源101、発光素子103
と発振回路105は図1の同番号を付したものと同じで
同じ動作をする。図7の7021、7022、7023
はスイッチ回路、7041と7042は容量Cのコンデ
ンサである。スイッチ回路7021、7022、702
3は、それぞれ端子a、b、c、sを持つ。そして、ス
イッチ回路7021、7022、7023の総ての端子
sは発振回路105の出力と接続し、発振回路105の
出力信号がLの信号の時、スイッチ回路7021、70
22、7023は端子aとcを導通させ、Hの時に端子
cとbを導通させる。ここで、スイッチ回路7021の
端子aは電源101の一端と、端子bはスイッチ回路7
022の端子bと、端子cはコンデンサ7041の一端
と接続し、スイッチ回路7022の端子cはコンデンサ
7042の一端と接続している。更にスイッチ回路70
23の端子cはコンデンサ7042の他端と接続し、端
子aは電源101の一端と接続し、端子bは発光素子1
03の一端と接続してある。電源101の他端、スイッ
チ回路7022の端子a、発光素子の他端はある共通電
位(記号▽)に接地されている。以上の構成となってい
る。<Structure> FIG. 7 is a diagram showing an electric structure of the light source of the present embodiment. In the figure, a power supply 101, a light emitting element 103
And the oscillating circuit 105 operate in the same manner as those of FIG. 7021, 7022, 7023 in FIG.
Is a switch circuit, and 7041 and 7042 are capacitors having a capacitance C. Switch circuits 7021, 7022, 702
3 has terminals a, b, c, and s, respectively. All terminals s of the switch circuits 7021, 7022, and 7023 are connected to the output of the oscillation circuit 105, and when the output signal of the oscillation circuit 105 is an L signal, the switch circuits 7021, 7022
The terminals 22 and 7023 conduct the terminals a and c, and conduct the terminals c and b when the terminals are at H level. Here, the terminal a of the switch circuit 7021 is connected to one end of the power supply 101 and the terminal b is connected to the switch circuit 7.
The terminal b and the terminal c of the switch circuit 022 are connected to one end of the capacitor 7041, and the terminal c of the switch circuit 7022 is connected to one end of the capacitor 7042. Further, the switch circuit 70
23, a terminal c is connected to the other end of the capacitor 7042, a terminal a is connected to one end of the power supply 101, and a terminal b is
03 is connected to one end. The other end of the power supply 101, the terminal a of the switch circuit 7022, and the other end of the light emitting element are grounded to a certain common potential (symbol ▽). The configuration is as described above.
【0042】<動作>次に動作を説明する。まず、発振
回路105の出力がLの時、スイッチ回路7021、7
022、7023は端子aとcを導通させるので、コン
デンサ7041の一端は電源101と他端は接地され、
同様にコンデンサ7042の一端は電源101と他端は
接地される。よって、コンデンサ7041、7042は
並列に電源101と接続されて電圧Vでコンデンサ70
41、7042を充電する。次に発振回路105の出力
がHの状態になると、スイッチ回路7021、702
2、7023はの各々の端子bとcを導通させるので、
コンデンサ7041と7042は直列接続となり、2つ
のコンデンサ7041と7042の電圧は2Vとなり、
この電圧が発光素子103に印加する。ここで、2V>
VF(>V)ならば、コンデンサ7041、7042が
放出する電荷量はC(2V−VF)となる。これが1秒
間にf回繰り返されるので、平均電流はC(2V−V
F)fとなる。<Operation> Next, the operation will be described. First, when the output of the oscillation circuit 105 is L, the switch circuits 7021, 7
022 and 7023 conduct the terminals a and c, so that one end of the capacitor 7041 is grounded at the other end of the power supply 101,
Similarly, one end of the capacitor 7042 is connected to the power supply 101 and the other end is grounded. Therefore, the capacitors 7041 and 7042 are connected in parallel to the power
41 and 7042 are charged. Next, when the output of the oscillation circuit 105 becomes H level, the switch circuits 7021 and 702
2, 7023 conducts the respective terminals b and c of
The capacitors 7041 and 7042 are connected in series, and the voltage of the two capacitors 7041 and 7042 becomes 2V,
This voltage is applied to the light emitting element 103. Here, 2V>
If VF (> V), the amount of charge released by the capacitors 7041 and 7042 is C (2V-VF). Since this is repeated f times per second, the average current is C (2V-V
F) f.
【0043】以上のように発光素子に必要な最低電圧以
下の電源電圧でも光源として機能させることが可能であ
る共に、第1の実施形態と同様に無駄な電力消費が無い
ので高効率である。本実施形態では2つのコンデンサを
並直切替して2Vの電圧を得たが、任意の個数nのコン
デンサを並直切替してnVの電圧を得ることが可能であ
ることはいうまでもない。As described above, it is possible to function as a light source even with a power supply voltage equal to or lower than the minimum voltage necessary for the light emitting element, and high efficiency is achieved because there is no useless power consumption as in the first embodiment. In this embodiment, two capacitors are switched in parallel to obtain a voltage of 2 V. However, it is needless to say that an arbitrary number n of capacitors can be switched in parallel to obtain a voltage of nV.
【0044】なお、V>VFの場合でも発光素子によっ
ては高電圧印加の方が発光効率の良い場合があり、本実
施形態を用いても良い。Even when V> VF, depending on the light emitting element, application of a high voltage may have higher luminous efficiency, and this embodiment may be used.
【0045】更に、第1の実施形態と同様に第2ないし
8の実施形態の調光手段が適用可能であり同様の効果が
ある。Further, similarly to the first embodiment, the light control means of the second to eighth embodiments can be applied, and the same effect can be obtained.
【0046】[第10の実施形態] <表示装置>上述の光源を液晶表示装置のバックライト
等の光源に用いることにより、液晶表示装置としての消
費電力が低減される。また、調光が容易な為に視認性の
良い表示が得られる。Tenth Embodiment <Display Device> By using the above-mentioned light source for a light source such as a backlight of a liquid crystal display device, the power consumption of the liquid crystal display device is reduced. In addition, since the dimming is easy, a display with good visibility can be obtained.
【0047】[第11の実施形態] <電子機器>上述の表示装置を電子機器に組み込むこと
により、電子機器としての消費電力が低減される。ま
た、見やすい表示がなされ電子機器の製品品質を向上さ
せることが出来る。Eleventh Embodiment <Electronic Apparatus> By incorporating the above-described display device into an electronic apparatus, the power consumption of the electronic apparatus can be reduced. In addition, an easy-to-read display is provided, and the product quality of the electronic device can be improved.
【0048】このような電子機器として、パーソナル・
コンピュータ、携帯電話機、デジタル・スチル・カメ
ラ、液晶テレビ、ビデオ録画機器のモニタ等々が挙げら
れる。As such electronic equipment, personal computers
Examples include a computer, a mobile phone, a digital still camera, a liquid crystal television, and a monitor of a video recording device.
【0049】[0049]
【発明の効果】以上説明したように本発明によれば、高
効率の光源が得られ容易に調光が出来るようになる。As described above, according to the present invention, a highly efficient light source can be obtained and light can be easily adjusted.
【図1】本発明の第1の実施形態に係る、光源の電気的
構成例を示す図。FIG. 1 is a diagram showing an example of an electrical configuration of a light source according to a first embodiment of the present invention.
【図2】本発明の第1の実施形態に係る、スイッチ回路
102の具体的な一構成例を示す図。FIG. 2 is a diagram showing a specific configuration example of a switch circuit 102 according to the first embodiment of the present invention.
【図3】本発明の第1の実施形態に係る、発振回路10
5の具体的な一構成例を示す図。FIG. 3 shows an oscillation circuit 10 according to the first embodiment of the present invention.
FIG. 5 is a diagram showing a specific configuration example of FIG.
【図4】本発明の第2の実施形態に係る、光源の電気的
回路構成を示す図。FIG. 4 is a diagram showing an electric circuit configuration of a light source according to a second embodiment of the present invention.
【図5】本発明の第2の実施形態に係る、発振回路40
5の具体的な一構成例を示す図。FIG. 5 shows an oscillation circuit 40 according to a second embodiment of the present invention.
FIG. 5 is a diagram showing a specific configuration example of FIG.
【図6】本発明の第5の実施形態に係る、光源の電気的
回路構成を示す図。FIG. 6 is a diagram showing an electric circuit configuration of a light source according to a fifth embodiment of the present invention.
【図7】本発明の第9の実施形態に係る、光源の電気的
回路構成を示す図。FIG. 7 is a diagram showing an electric circuit configuration of a light source according to a ninth embodiment of the present invention.
【図8】従来技術の光源の電気的回路構成を示す図。FIG. 8 is a diagram showing an electric circuit configuration of a light source according to the related art.
101…電源 102…スイッチ回路 103…発光素子 104…コンデンサ 105…発振回路 201…Pch電界効果トランジスタ 202…Nch電界効果トランジスタ 301…シュミットトリガ入力の論理反転回路 302…コンデンサ 303…抵抗器 DESCRIPTION OF SYMBOLS 101 ... Power supply 102 ... Switch circuit 103 ... Light emitting element 104 ... Capacitor 105 ... Oscillation circuit 201 ... Pch field effect transistor 202 ... Nch field effect transistor 301 ... Logical inversion circuit of Schmitt trigger input 302 ... Capacitor 303 ... Resistor
───────────────────────────────────────────────────── フロントページの続き Fターム(参考) 2H091 FA44Z FA45Z FD07 FD22 GA11 3K007 AB03 EB00 EC00 GA04 3K073 AA16 AA54 BA28 CE17 CG35 CG42 CG45 CG46 CJ17 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H091 FA44Z FA45Z FD07 FD22 GA11 3K007 AB03 EB00 EC00 GA04 3K073 AA16 AA54 BA28 CE17 CG35 CG42 CG45 CG46 CJ17
Claims (16)
と交互に接続させる第1のスイッチ素子を具備すること
を特徴とする光源。1. A light source comprising: a capacitor; a power supply; a light-emitting element; and a first switch element that connects the capacitor alternately with the power supply or the light-emitting element.
と前記複数のコンデンサを直列接続して前記発光素子と
接続する状態のいずれかに交互に切り替える第2のスイ
ッチ素子を具備することを特徴とする光源。2. A plurality of capacitors, a power supply, a light emitting element, and a state in which the plurality of capacitors are connected in parallel with the power supply or a state in which the plurality of capacitors are connected in series and connected to the light emitting element. A light source comprising a second switch element that alternately switches the light source.
記コンデンサを前記電源又は前記発光素子のいずれかと
交互に接続させる切替周期を可変させる周期可変手段を
具備することを特徴とする請求項1乃至2いずれか記載
の光源。3. The apparatus according to claim 1, wherein said first or second switch element includes a cycle changing means for changing a switching cycle for alternately connecting said capacitor to either said power supply or said light emitting element. 3. The light source according to any one of claims 1 to 2.
可変手段が手動で前記切替周期を変化させることを特徴
とする光源。4. The light source according to claim 3, wherein said period changing means manually changes said switching period.
手段が外光の強さに応じて前記切替周期を変化させるこ
とを特徴とする光源。5. The light source according to claim 3, wherein said variable means changes said switching period according to the intensity of external light.
手段が手動及び外光の強さに応じて前記切替周期を変化
させることを特徴とする光源。6. The light source according to claim 3, wherein said variable means changes said switching period manually or according to the intensity of external light.
ンサの容量を変化させる容量可変手段を具備することを
特徴とする請求項1乃至2いずれか記載の光源。7. The light source according to claim 1, further comprising a capacitance changing unit that changes a capacitance of the capacitor or the plurality of capacitors.
可変手段が手動で前記コンデンサまたは前記複数のコン
デンサの容量を変化させることを特徴とする光源。8. The light source according to claim 7, wherein said variable capacitance means manually changes the capacitance of said capacitor or said plurality of capacitors.
可変手段が外光の強さに応じて前記コンデンサまたは前
記複数のコンデンサの容量を変化させることを特徴とす
る光源。9. The light source according to claim 7, wherein said capacitance varying means changes the capacitance of said capacitor or said plurality of capacitors according to the intensity of external light.
量可変手段が手動及び外光の強さに応じて前記コンデン
サまたは前記複数のコンデンサの容量を変化させること
を特徴とする光源。10. The light source according to claim 7, wherein said capacitance varying means changes the capacitance of said condenser or said plurality of condensers manually and according to the intensity of external light.
段を具備することを特徴とする請求項1乃至2いずれか
記載の光源。11. The light source according to claim 1, further comprising the variable period unit and the variable capacitance unit.
周期可変手段及び前記容量可変手段の少なくとも一方の
可変手段について、手動または外光の強さに応じて前記
切替周期または前記コンデンサまたは前記複数のコンデ
ンサの容量を変化させることを特徴とする光源。12. The light source according to claim 11, wherein at least one of the period variable unit and the capacitance variable unit is manually or in accordance with the intensity of external light, the switching period or the capacitor or the plurality of capacitors. A light source characterized by changing the capacity of a capacitor.
エレクトロ・ルミネッセンスであることを特徴とする請
求項1乃至12いずれか記載の光源。13. The light source according to claim 1, wherein the light emitting element is a light emitting diode or electroluminescence.
たことを特長とする電子機器。14. An electronic apparatus comprising the light source according to claim 1.
たことを特長とする表示装置。15. A display device comprising the light source according to claim 1. Description:
ことを特長とする電子機器。 【発明の属する技術分野】本発明は、例えば、液晶表示
装置のバックライト等に用いられる光源に関する。16. An electronic apparatus comprising the display device according to claim 15. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source used for, for example, a backlight of a liquid crystal display device.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
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JP2001091432A JP2002289374A (en) | 2001-03-27 | 2001-03-27 | Light source, display equipment, and electronic device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2001091432A JP2002289374A (en) | 2001-03-27 | 2001-03-27 | Light source, display equipment, and electronic device |
Publications (1)
Publication Number | Publication Date |
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JP2002289374A true JP2002289374A (en) | 2002-10-04 |
Family
ID=18946048
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JP2001091432A Withdrawn JP2002289374A (en) | 2001-03-27 | 2001-03-27 | Light source, display equipment, and electronic device |
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Cited By (7)
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WO2005078810A1 (en) * | 2004-02-12 | 2005-08-25 | Citizen Watch Co., Ltd. | Light source driver circuit, illuminating apparatus, display apparatus, field sequential color system liquid crystal display apparatus, and information device |
JP2007080572A (en) * | 2005-09-12 | 2007-03-29 | Hamamatsu Photonics Kk | Light control circuit for liquid crystal back light |
JP2007173697A (en) * | 2005-12-26 | 2007-07-05 | Denso Corp | Light-emitting diode-driving device |
JP2007189103A (en) * | 2006-01-13 | 2007-07-26 | Denso Corp | Light-emitting diode driving device |
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WO2005078810A1 (en) * | 2004-02-12 | 2005-08-25 | Citizen Watch Co., Ltd. | Light source driver circuit, illuminating apparatus, display apparatus, field sequential color system liquid crystal display apparatus, and information device |
JPWO2005078810A1 (en) * | 2004-02-12 | 2007-10-18 | シチズンホールディングス株式会社 | Light source driving circuit, illumination device, display device, field sequential color liquid crystal display device and information device |
CN100426543C (en) * | 2004-02-12 | 2008-10-15 | 西铁城控股株式会社 | Light source driver circuit, illuminating apparatus, display apparatus, field sequential color system liquid crystal display apparatus, and information device |
JP2007080572A (en) * | 2005-09-12 | 2007-03-29 | Hamamatsu Photonics Kk | Light control circuit for liquid crystal back light |
JP2007173697A (en) * | 2005-12-26 | 2007-07-05 | Denso Corp | Light-emitting diode-driving device |
JP2007189103A (en) * | 2006-01-13 | 2007-07-26 | Denso Corp | Light-emitting diode driving device |
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WO2007134991A2 (en) * | 2006-05-18 | 2007-11-29 | Thomson Licensing | Driver for controlling a light emitting element, in particular an organic light emitting diode |
JP2009537852A (en) * | 2006-05-18 | 2009-10-29 | トムソン ライセンシング | Driver for controlling light emitting elements (DO), especially organic light emitting diodes |
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JP2016134282A (en) * | 2015-01-19 | 2016-07-25 | パナソニックIpマネジメント株式会社 | Lighting device, illumination equipment and illumination system |
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