Abstract:
An illumination system including light source elements including at least a first element for emitting a first color light and a second element for emitting a second color light whose color is different from the first color light. A screen receives the projecting light from the first and second color lights from the light source elements, and a plate is placed between the light source elements and the screen, thereby defining first and second areas, wherein the first and second areas have different properties of conducting light from each other. In this system, the first color light is projected through the plate on a first area of the screen and the second color light is projected through the plate on a second area of the screen. Then, the first and second areas overlap with each other.

Description:
BACKGROUND OF THE INVENTION 
   This invention relates to an illumination system for illuminating surface of various kinds of device with colored lights. The lights are cast from the inside of the device to the surface to project an image such as an emblem, symbol, trademark and geometrical pattern on the surface. Particularly, the illumination system is suitably incorporated with a portable electronic device. 
   Recently, some of portable electronic devices such as a portable telephone terminal, PDA (personal data assistant) and wrist watch have a illumination system for emitting various color lights in response to a predetermined action of the devices. 
   For example, a illumination system of a portable telephone terminal project an emblem on the surface of the portable telephone terminal when the terminal receives a call, or during the terminal is establishing a connection with another telephone terminal. 
   A portable telephone terminal  101  shown in  FIG. 1  has a foldable housing  102  and is now folded in  FIG. 1 . On an upper housing  103 , an conventional illuminator  104 , an auxiliary display device  105  and an antenna  106  is installed. The illuminator  104  emits light to Indicate an arrival of a call or establishment of a connection with another telephone terminal. The sub display device  105  displays information when the foldable housing  102  is folded. The antenna  106  directs incoming and outgoing radio waves. 
   As shown in  FIG. 2 , the illuminator  104  includes a light source unit  107  and a screen  108 . As shown in  FIG. 3 , the light source unit  107  includes a red LED  107   r , a green LED  107   g  and a blue LED  107   b  on a print-circuit plate Lights emitted from the LEDs are cast on the screen  108 . 
   The LEDs blink according to a predetermined blinking pattern in order to cast a single one or a mixture of two or three colors on the screen  109 . For example, if the blinking pattern consists of combinations of ON/OFF of the LEDs, then the screen  108  is colored in one of red, green, blue, yellow, cyan, magenta, white and black. 
   Whichever a single LED or plural LEDs emit, a single color is cast on the screen  108  at one time as shown in  FIG. 4 . Therefore, the screen  108  cannot be divided into plural areas each of which has a different color from each other. Consequently, it is unable to express on the screen  108  that an object with a color moves on a background with another color. 
   Related arts are disclosed on Japanese Patent Publication No. 2001-166738, in which a group of LEDs including a red, green and blue LEDs 
   SUMMARY OF THE INVENTION 
   This invention provides the following an illumination system and an electronic device with the illumination system. 
   According to one aspect of the present invention, an illumination system including: light source elements including at least a first element for emitting a first color light and a second element for emitting a second color light whose color is different from the first color light; a screen cast the first and second color lights from the light source elements; and a plate which is placed between the light source elements and the screen, and comprises first areas and second areas, the first and second areas having different properties of conducting light from each other, wherein: the first color light is cast through the plate on a first spot of the screen; the second color light is cast through the plate on a second spot of the screen; and the first and second spots overlap with each other is provided. 
   The light source elements are for example arranged in line with each other. Alternatively, the light source elements may be arranged in vertexes of a polygon. The light axes of the light source elements are preferably parallel but offset with each other. 
   The first areas of the plate may be openings opened through the plate. It is preferable that the arrangement of the first and second areas on the plate expresses a design to be cast on the screen. 
   The plate may be a transparent or translucent plate. In this case, the plate is partially painted with lightproof paint as the second areas. Alternatively, the plate may be an opaque plate with penetrable areas for conducting light In this case, the penetrable areas may be openings opened through the plate, or transparent members fit into the plate. 
   The light source elements may be dots emitting light. The light source elements may include a red, green and blue light source elements for emitting red, green and blue light, respectively. Instead, the light source elements may include a cyan, magenta and yellow light source elements for emitting cyan, magenta and yellow light, respectively. Further, light emitted from one of the red, green and blue light source elements may be partially mixed with a part of light emitted from the other. Similarly, light emitted from one of the cyan, magenta and yellow light source elements may be partially mixed with a part of light emitted from the other. 
   Each of the light source elements may blink according to a predetermined blinking pattern. In this case, for example, the blinking pattern is predetermined according to the shape of the first and/or second area and to the arrangement of the first and second areas on the plate. The blinking pattern may be predetermined according to the arrangement of the plate, the light source elements and the screen. The blinking pattern may be predetermined according to the arrangement of the light source elements. 
   At least one filter member may be placed between the plate and the light source elements or between the plate and the screen. 
   At least one of the plate and the screen may be detachable from the illumination system. The plate and the screen may be integrated with each other. 
   The screen is for example a transparent or translucent plate with a diffusion layer on at least one surface of the plate. In this case, the diffusion layer diffuses light from the light source elements. The diffusion layer is preferably a white layer. The diffusion layer may be formed on a part of a surface of the plate. In this case, the diffusion layer and the rest of the surface express a design to be illuminated with the light from the light source elements. 
   Additionally, according to another aspect of the present invention, an electronic device including the above-mentioned illumination system is provided. One example of the electronic device is a portable communication device. In this case, it is preferable that the illumination system is activated in response to a predetermined operation of the portable communication device. 
   According to one aspect of this invention, light sources emit colors each of which is different from each other. Part of one of the colors is directly cast on a screen as it has been emitted. Other part of the color is mixed with a singular or plural other colors and then cast on the screen. As a result, gradual color change occurs on the screen and therefore, according to the present invention, decorativeness of a portable electronic device can be improved. 
   According to another aspect of the present invention, pattern cast on the screen is changed in accordance with emissions from the light sources. The emissions are controlled by inputs to the light sources. Therefore, according to the present invention, temporal response of the cast pattern can be easily made. 
   According to another aspect of the present invention, spots of a color mixture are cast on the screen. For example, it is assumed that the light sources are red, green and blue light emitting elements each of which is controlled by on/off switching. In this case, when the emitting elements are switched in response to a suitable switching pattern, the spot seems to move around on the screen. This aspect provides visual amusement on the screen. 
   According to another aspect of the present invention, various sizes of light spots are cast on the screen at the same time to supply perspective on the screen. 
   These aspects are achieved by a simple structure including a conduit plate between the screen and the light sources, No moving parts are required. Therefore, the present invention can be easily implemented in portable electronic devices, e.g. cellular phone terminals, without disturbing miniaturization, weight saving, low-profiling and lowering the cost of production of the devices. 

   
     BRIEF DESCRIPTION OF THE DRAWING; 
       FIG. 1  shows a top view of a folding communication device with an illumination system with being folded; 
       FIG. 2  shows a schematic diagram of a conventional illumination system; 
       FIG. 3  shows a cross section diagram of the conventional illumination system shown in  FIG. 2 ; 
       FIG. 4  shows a screen view cast by the conventional illumination system shown in  FIGS. 2 and 3 ; 
       FIG. 5  shows a top view of a folding communication device with an illumination system of a first embodiment of the present invention when it is folded; 
       FIG. 6  shows a top view of the folding communication device shown in  FIG. 5  with being unfolded; 
       FIG. 7  shows a block diagram of the folding communication device shown in  FIGS. 5 and 6 ; 
       FIG. 8  shows a cross section diagram of a sub screen including the illumination systems of the first embodiment; 
       FIG. 9  shows a schematic diagram of the illumination system of the first embodiment; 
       FIG. 10  shows an arrangement of three light emitting elements; 
       FIG. 11  shows an example of cover for covering a sub screen of the folding communication device; 
       FIG. 12  shows a cross section diagram of the illumination system of the first embodiment; 
       FIG. 13  shows a schematic diagram for use in describing the screen cast colored lights from the light emitting elements; 
       FIG. 14  shows a block diagram for use in describing an LED driver  7 ; 
       FIG. 15  shows a timing chart for use in describing switching of the light emitting elements; 
       FIG. 16A  shows a schematic diagram for use in describing movement of light spots on the screen; 
       FIG. 16B  shows a schematic diagram for use in describing movement of light spots on the screen; 
       FIG. 16C  shows a schematic diagram for use in describing movement of light spots on the screen; 
       FIG. 17  shows a schematic cross section diagram of the illumination system of the first embodiment; 
       FIG. 18A  shows a schematic cross section diagram for use in describing movement of light spots on the screen; 
       FIG. 18B  shows a schematic cross section diagram for use in describing movement of light spots on the screen; 
       FIG. 19  shows a cross section diagram of a screen of a second embodiment of the present invention; 
       FIG. 20  shows a cross section diagram of a screen of a third embodiment of the present invention; and 
       FIG. 21  shows a top view of the screen of the third embodiment. 
       FIG. 22  shows a schematic cross-section diagram of the illumination system of the fourth embodiment. 
       FIG. 23  shows a schematic diagram of the illumination system of the fifth embodiment. 
       FIG. 24  shows a schematic cross-section diagram of the illumination system of the sixth embodiment. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Description will be made about a first embodiment of the present invention. The first embodiment is a portable communication device  1 , e.g. a cellular telephone terminal. With reference to  FIGS. 5 and 6 , the portable communication device  1  has a foldable housing  2  which includes an upper housing  21  and a lower housing  22 . The upper housing  21  and lower housing  22  are connected with each other via a hinge  19  and rotate on the hinge  19  to fold/unfold the foldable housing  2 . 
   As shown in  FIG. 7 , in the foldable housing  2 , the portable communication device  1  includes a controller  3 , a memory  4 , an upper illuminator  5 , a lower illuminator  6 , a LED driver  7 , an antenna  8 , a wireless communicator  9 , an input device  11 , a main display  12 , an auxiliary display  13 , an electronic camera unit  14 , a ringer  15 , a ringer driver  16 , a speaker  17 , and a microphone  18 . 
   The controller  3  includes a CPU (Central Processing Unit) which reads/writes the memory  4  and executes programs stored in the memory  4  to control other units of the portable communication device  1 . For example, the following programs are executed on the controller  3 : a communication control program for controlling communication procedures such as sending a call to a telephone number; a input control program for processing data input via key switches of the input device  11 ; an illumination control program for controlling the LED driver  17  to switch LEDs of the upper Illuminator  5  and/or the lower illuminator  6  in response to receiving a call and while establishing a connection between other communication device; a display control program for controlling the main display  12  and auxiliary display  13  to display image data (e.g. image data generated by the electronic camera unit  14 ); a web browser program for communicating with a web server and interpreting web page data; a mailer program for communicating with a mail server and managing mail data and so on. 
   The memory  4  stores program executed by the controller  3  and data read/written by the controller  3 . The memory  4  consists of semiconductor memory and has a program storage area and a data storage area. The program storage area stores the above-mentioned programs. The data storage area stores data of configuration, communication log, address book, blinking pattern and so on. According to the blinking pattern information data, the upper and lower illuminators  5  and  6  are switched on/off. The data storage area further stores image data output from the electronic camera unit  14 , register data and flag data for executing a program on the controller  3 . 
   According to the illumination control program, in response to receiving a call or while establishing a connection, the controller  3  makes LEDs of the upper and lower illuminators  5  and  6  to blink with reference to the blinking pattern data. 
   The illumination control program states the procedure that, in response to receiving a call or while establishing a connection, the controller  3  makes the LEDs of the upper and lower illuminators  5  and  6  to blink with reference to the blinking pattern data. Although in this embodiment, the upper and lower illuminators  5  and  6  share a single blinking pattern data, in another embodiment, the illuminators may refer different blinking pattern data with each other. 
   The blinking pattern data are time series data. Each of the upper and lower illuminators  5  and  6  includes a red LED, a green LED and a blue LED. On-off states of three LEDs are expressed as a set of three bits data. For example, a first, second and third bit of the data set are related with on-off states of the red, green and blue LEDs, respectively. In this case, the data set (0,0,0) represents that all of the red, green and blue LEDs are off, the data set (0,0,1) represents that only the read LED is on; the data set (0,1,0) represents that only the green LED is on; the data set (1,0,0) represents that only the blue LED is on; the data set (1,0,1) represents that only the green LED is off; the data set (1,1,0) represents that only the red LED is off; the data set (0,1,1) represents that only the blue LED is off; and the data set (1,1,1) represents that all of the LEDs are on. 
   In this embodiment, the upper and lower illuminators  5  and  6  illuminate to inform of receiving a call and to decorate the portable communication device  1 . 
   As shown in  FIGS. 6 and 8 , two illumination systems, or the upper and lower illuminators  5  and  6  are installed beside the upper and lower ends of the auxillary display  13 , respectively. The upper illuminator  5  includes a light source unit  31 , a conduit plate  32  and a screen  33 , as shown in  FIG. 9 . Similarly, the lower illuminator  6  includes a light source unit  43 , a conduit plate  44  and a screen  45 , Hereinafter the description about the upper illuminator  5  is basically adaptive to that about the lower illuminator  6 . 
   As shown in  FIG. 9 , the conduit plate  32  is inserted between the light source unit  31  and the screen  33 . The conduit plate  32  has penetrable areas  32   a   1 ,  32   a   2 ,  32   a   3 , . . . and opaque area  32   b . The penetrable areas  32   a   1 ,  32   a   2 ,  32   a   3 , . . . can transmit light and may be made of translucent or transparent material, or openings through the conduit plate  32 . The opaque area  32   b  blocks the passage of light from the light source unit  31 . Therefore, lights emitted from the light source unit  31  are cast on the screen  33  via the penetrable areas  32   a   1 ,  32   a   2 ,  32   a   3 , . . . on the conduit plate  32 . 
   In this embodiment, the penetrable areas are openings on the conduit plate  32 . The conduit plate  32  is an opaque substrate, at least one of surfaces of which is covered with a opaque layer. The openings  32   a   1 ,  32   a   2 ,  32   a   3 , . . . are formed predetermined positions on the opaque substrate. 
   The openings have an approximate circle form and are regularly formed on the substrate. In this embodiment, the diameter of the openings is about 0.5 mm, the pitch of the openings is about 1.0 mm. 
   As shown in  FIG. 12 , the light source unit  31  includes a red LED  34 , a green LED  35  a blue LED  36  and a PCB (printed-circuit plate)  37 . The LEDs  34 ,  35  and  36  are arranged on the PCB  37  in order that the centers of the LEDs  34 ,  35  and  38  form a triangle on the PCB  37 . Each light rays from the LEDs  34 ,  35  and  36  travels through the holes  32   a   1 ,  32   a   2 ,  32   a   3 , . . . to the screen. 
   With reference to  FIGS. 8 and 11 , the upper illuminator  5 , the lower illuminator  6  and the auxiliary display  13  are covered with a cover  38 , which is made of translucent material, except for a transparent window  39 . Image displayed on the auxiliary display  13  is transmitted through the transparent window  39  toward its user&#39;s eyes. The screens  33  and  45  are formed on the inner surface of the cover  39  to oppose the light source units  31  and  43 , respectively. The screen  33  has a white layer  41  for diffusing light from the light source unit  31 . Similarly, the screen  45  has a white layer  46  for diffusing light from the light source unit  43 . 
   The distance between the light source unit  31  and the conduit plate  32 , the distance between the conduit plate  32  and the screen  33 , the sizes, forms and arrangement of the penetrable areas  32   a   1 ,  32   a   2 , . . . , and the arrangement of the red LED  34 , the green LED  35  and the blue LED  36  on the PCB  37  are predetermined based on an illumination pattern to be displayed on the screen  33 . For example, they are experimentally predetermined. The illumination pattern expresses arrangement of colors and temporal response of the arrangement on the screen  33 . Namely, the illumination pattern may be change of patterns displayed on the screen  33 , change of color arrangement in a pattern, and combination of these changes. The illumination pattern actually displayed on the screen  33  is eventually determined based on the blinking pattern of the LEDs. In this embodiment, the distance between the light source unit  31  and the conduit plate  32  is about 0.3 mm, and the distance between the conduit plate  32  and the screen  33  is about 1.0 mm. 
   The light emitted from the LEDs passes thorough routes described as following and as shown in  FIG. 12 . 
   The light rays emitted from the LEDs  34 ,  35  and  36  are first cast on the conduit plate  32 , passes thorough the openings  32   a   1 ,  32   a   2 ,  32   a   3 ,  32   a   4  and  32   a   5  on the conduit plate  32 , and then arrive on the screen  33 . 
   The opening  32   a   1  is opened at a position on the conduit plate  32  where the light from the green LED  35  and the blue LED  36  seldom or never arrive. Therefore, the light passing through the opening  32   a   1  is almost red light. Similarly, the light passing through the opening  32   a   5  is almost blue light. Namely, the opening  32   a   1  mainly conducts red light and the opening  32   a   5  mainly conducts blue light Each of the rest openings  32   a   2 ,  32   a   3  and  32   a   4  conducts red, green and blue light. Therefore, the colors of the light rays through the openings  32   a   2 ,  32   a   3  and  32   a   4  are mixtures of red, green and blue, although the mixtures have a different mixing ratio of red, green and blue from each other. 
   The light rays through the openings  32   a   1 ,  32   a   2 ,  32   a   3 ,  32   a   4  and  32   a   5  are mixed between the conduit plate  32  and the screen  33  and then cast on the screen  33 . In  FIG. 12 , red light is cast on the left end of the screen  33 , blue light is cast on the right end of the screen  33 , and between the left and right ends of the screen  33 , mixed color light whose mixing ratio is dependent on a position on the screen  33  is cast on the screen  33 . 
   As a result, red, green, blue spots of light are cast on the screen  33 , spots having a mixed color of two or three of red, green and blue are cast on the screen  33 , and in addition, these spots cast from openings on the conduit plate  32  are partly cast on a same area of the screen  33  with each other to make another color on the area. 
   For example, as shown in  FIG. 13 , each of a primary color (red, green or blue) spot  41   a , an yellow spot  41   b , a magenta spot  41   c , a cyan spot  41   d  and a white spot  41   e  is cast through an opening on the conduit plate  33 . The yellow spot  41   b  is partly cast on the same area with the white spot  41   e . As a result, the union of the spots  41   b  and  41   e  on the screen  33  has a different color from both yellow and white from the opening on the conduit plate  32 . Similarly, mixture colors of the primary color and white, magenta and white and cyan and white appear on the screen  33 . 
   The LED driver  14  includes a FIFO (First In First Out memory)  51 , an output port register  52 , a read-out signal generating circuit  53 , and a drive signal output circuit  54 . The FIFO  51  read blinking pattern data of the LEDs from the memory  4  and outputs in queue order. The output port register  52  stores output from the FIFO  51  and outputs to the drive signal output circuit  54 . The read-out signal generating circuit  53  outputs a read-out signal to the FIFO  51  in accordance with a clock signal. The drive signal output circuit  54  outputs drive signal for driving the LEDs of the upper and lower illuminators  5  and  6 . 
   The wireless communicator  9  includes a RF (radio frequency) circuit, a modulator/demodulator circuit, a base band circuit and so on. The wireless communicator  9  modulates sound or other data to radio waves, outputs the radio waves via the antenna  8 , receives radio waves via the antenna  8 , demodulates the radio waves to sound or data, establishes voice or data communication in accordance with predetermined protocols. 
   The input device  11  is a keypad for example including cursor keys for inputting a direction to move a cursor on the main display  12 , numeric keys for inputting numbers, and function keys related to predetermined functions of the portable communication device  1 . For example, function keys are browser key for executing a browser program on the portable communication device  1  to display web pages on the main display  12 , an enter key for confirming user input, menu keys for displaying function menu of the portable communication device  1  on the main display  12 , an input method switching key for switching input method, an address book key for displaying an address book on the main display  12 , a clear key for erasing input or return state of the main display  12 , a power key for turning on/off the portable communication device  1 , and a camera key for activating the electronic camera unit  14  and for pressing the shutter of the camera unit  14 . 
   The main display  12  is for example a transmissive LCD and is arranged on a front face of the upper housing  21  which is aligned with a front face of the lower housing  22  when the portable communication device  1  is folded. The main display  12  includes an LCD panel, a backlight, and a driver circuit. 
   The LCD panel is for example a transmissive liquid crystal display panel with TFT (Thin Film Transistor) structure, which includes a TFT substrate embedded TFTs and transparent pixel electrodes, an opposite substrate which includes a color filer and opposes to the TFT substrate with several-micrometer-gap, and a pair of polarizes arranged outside of the substrates. 
   The auxiliary display  13  is for example a transmissive LCD panel and is arranged on a back face of the upper housing  21 , which displays time, arrival of calling, receiving a mail etc. when the portable communication device  1  is folded. 
   As shown in  FIGS. 5 and 7 , the electronic camera unit  14  includes a hole  56 , a lens  57 , image sensors  58  and an image processor  59 . The hole  56  is arranged on the back face of the upper housing  21  to guide the light coming from objects to the lens  57 . The lens  57  is arranged in the hole  56 , is for example a standard lens and focuses on the image sensors  58 . The image sensors  58  are for example CCD (Charge Coupled Devices) and transform photon flux thorough the lens  57  into a charge. The image processor  59  performs analog to digital translation to translate from analog image signals output by the image sensors  58  to digital image signals and applies gamma correction, color space conversion and/or other image processing to the digital image signals. 
   Next, description will be made about the operation of the portable communication device  1 . 
   After turning the portable communication device  1  on, the controller  3  enters a waiting mode for standing by for inputting via the input device  11  or receiving a call from another communication device, and displays on the main display  12  that the portable communication device  1  is in the waiting mode. 
   When the device  1  is in the waiting mode, in response to inputting via the device  1  or receiving a call, the controller  3  controls the LED driver  7  to blink the red, green and blue LEDs  34 ,  35   36  of the light source unit  107  according to a predetermined blinking pattern data. As a result, a desired illumination pattern corresponding to the blinking pattern data is performed on the screens  33  and  45 . 
   Namely, the controller  3  reads the blinking pattern data from the memory  4  and writes it to the FIFO  51 . Then, as shown in  FIG. 15 , the read-out signal generating circuit  53  generates a read-out signal P 1  according to a clock signal. The circuit  53  starts this signal generation in response to a start signal that is output from the controller  3 . 
   In response to the read-out signal P 1 , the FIFO  51  writes the blinking pattern data to the output port register  52 . The output port register  52  outputs port output signals PR, PG and PB for driving the red, green and blue LEDs respectively. The drive signal output circuit  54  drives the LEDs according to the port output signals PR, PG and PB. 
   As described above, the FIFO  51  sequentially outputs the blinking pattern data to the output port register  52  and then the amount of the data that remains in the FIFO  51  reduces. When the remaining data becomes a predetermined amount, the FIFO  51  requests the controller  3  to provide additional data. In response to the request, according to the amount of the free space in the FIFO  51 , the controller  3  reads the following blinking pattern data from the memory  4  and then sets the data to the FIFO  51 . 
   As shown in  FIG. 15 , before the time instant t 1  at which the controller  3  detects receiving a call, namely in a unit time period T 1  (t|t 1 ), all of the port output signals PR, PG and PB are low or L. In this time period, the red, green and blue LEDs  34 ,  35  and  36  are all off and consequently, no color is cast on the screens. 
   Next, in a time period T 2  (t 1 |t|t 2 ), the port output signals PR, PG and PB are H, L and L, respectively and only the red LED  34  emits to cast red light on the screen. 
   Similarly: in a unit time period T 3  (t 2 |t|t 3 ), only the port output signal PG is H; in a unit time period T 4  (t 3 |t|t 4 ), only the signal PR is L; in a period T 5  (t 4 |t|t 5 ), only the signal PB is L; in a period T 6  (t 5 |t|t 6 ), only the signal PG is L; in a period T 7  (t 6 |t|t 7 ), only the signal PR Is H; in a period T 8  (t 7 |t|t 8 ), all of the signals PR, PG and PB are L; in a period T 9  (t 8 |t|t 9 ), all of the signals PR, PG and PB are H; and; in a unit time period T 10  (t 9 |t|t 10 ), only the port output signal PR is L. 
   In the periods T 4 , T 5 , T 6 , T 9  and T 10 , two or three LEDs emit at once and two or three color light rays are cast on the conduit plate  32 . Some colors are mixed through the conduit plate  32  and then original colors emitted by the LEDs and the mixture colors are cast on the screen  33 . For example, in the period T 9 , red, green and blue are mixed through the conduit plates  32  to produce white. Two of red, green and blue are mixed through the conduit plates  32  to produce yellow, magenta or cyan. On the screen  33 , two of red, green, blue, white, yellow, magenta and cyan are mixed to produce another color. 
   For example, illumination pattern appears on the screens  33  and  45  as shown in  FIGS. 16A ,  16 B and  16 C, that show illumination patterns displayed on the screen  33  in a series of three time periods. 
   In  FIG. 16A , three spotlights  61   a ,  61   b  and  61   c  are cast on an area of the screen  33  for a first unit time period. The sizes and colors of the spotlights  61   a ,  61   b  and  61   c  are different from each other. Colors of the spotlights are three of red, green, blue, white, yellow, magenta and cyan. Additionally, two or three of the spotlights partially overlap and as a result another color is produced. 
   In a second period, as shown in  FIG. 16B , three spotlights  62   a ,  62   b  and  62   c  are cast on the area. The sizes and colors of the spotlights  62   a ,  62   b  and  62   c  are different from each other. The colors of the spotlights  62   a ,  62   b  and  62   c  are the same as those of the spotlights  61   a ,  61   b  and  61   c  respectively. The centers of the spotlights  62   a ,  62   b  and  62   c  are on substantially the same position as those of the spotlights  61   a ,  61   b  and  61   c  respectively. The sizes of the spotlights  62   a ,  62   b  and  62   c  are substantially the same as those of the spotlights  61   c ,  61   a  and  61   b  respectively. 
   In a third period, as shown in  FIG. 16   c , three spotlights  63   a ,  63   b  and  63   c  are cast on the area. The sizes and colors of the spotlights  63   a ,  63   b  and  63   c  are different from each other. The colors of the spotlights  63   a ,  63   b  and  63   c  are the same as those of the spotlights  62   a ,  62   b  and  62   c  respectively. The centers of the spotlights  63   a ,  63   b  and  63   c  are on substantially the same position as those of the spotlights  62   a ,  62   b  and  62   c  respectively. The sizes of the spotlights  63   a ,  63   b  and  63   c  are substantially the same as those of the spotlights  62   a ,  62   b  and  62   c  respectively. 
   The size of a spot on the screen caused by a light ray from a LED depends on the distance between the LED and the hole through which the light ray is cast on the screen. If the source LED is closer to the hole, then the spot is larger. Therefore, the sizes and positions of spots on the screen change in response to blinking of the red, green and blue LEDs  34 ,  35  and  36 . As a result, movements of spotlights are displayed on the screen. 
   With reference to  FIG. 16A ,  16 B and  FIG. 16C , the spot  61   a  seems to move to the spot  62   b  and then to move to the spot  63   c . The spot  61   b  seems to move to the spot  62   c  and then to move the spot  63   a . The spot  61   c  seems to move to the spot  62   a  and then to move to the spot  63   b . Namely, the spots seem to revolve in the screen. Further, color of an area of the screen seems to change. 
   Herein, the structure of the upper Illuminator  5  will be described in detail. As shown in  FIG. 17 , it is assumed that relatively large penetrable area  32   a  is installed at the center of the conduit plate  32  and the distance between the red LED  34  and the blue LED  36  is longer than that between the other combinations of the LEDs. 
   In the time period T 9  of  FIG. 15 , namely when all of the LEDs are on, each of red, green and blue rays is cast through the penetrable area  32   a  on the screen  33 . 
   On the screen  33 : an area  65   a  mainly receives blue light; an area  65   b  mainly receives blue and green light to produce cyan; an area  65   c  receives red, green and blue light to produce white; an area  65   d  mainly receives red and green light to produce yellow; and an area  65   e  mainly receives red light. Blue, cyan, white, yellow and red are displayed on the area  65   a ,  65   b ,  65   c ,  65 : and  65   e  respectively. As a result, the screen  33  displays plural colors at once. It is noted that, in conventional techniques, there Is no conduit plate  32  between the light source  37  and the screen  33  so that all areas on the screen only displays white. 
   From the period T 4  to T 5 , the screen  33  displays as shown in  FIG. 18A  and  18 B. In the period T 4 , the green and blue LEDs  35  and  36  emit to display a blue area  66   a , a cyan area  66   b  and a green area  66   c  on the screen  33 . Then, in the period T 5 , the red and green LEDs  34  and  35  emit to display a green area  67   a , a yellow area  67   b  and a red area  67   c  on the screen  33 . As a result, spots on the screen  33  seem to move from the areas  66   a ,  66   b  and  66   c  to  67   a ,  67   b  and  67   c  with changing their colors. 
   As described above, spots on the screen  33  are displayed as if they move around on the screen  33  with changing their colors. Similarly to the upper illuminator  5 , the lower illuminator  6  operates to display spots on the screen  46 . In this embodiment, the controller  3  makes the LED driver  7  blink the red, green and blue LEDs  34 ,  35  and  36  to display Illumination pattern on the screens  33  and  45 , not only when the portable communication device  1  receives a call, but also while the portable communication device  1  is establishing a connection to another communication device. 
   According to this embodiment, the LEDs emit colors that are different from each other and cast all of the colors on the screen at once. Compared with this embodiment, according to a conventional system, even if the system includes plural LEDs that emit different colors from each other, only a single color is cast on the screen at once. 
   According to this embodiment, colors are cast through a penetrable area on the conduit plate, and then the colors partially overlap with each other on the screen to produce other colors. Therefore, the number of colors displayed on the screen at once further increases. 
   According to the embodiment, each of the LEDs blinks in accordance with a different blinking pattern. A blinking pattern of a LED Is independent on that of another LED. In this embodiment, three LEDs are installed and consequently, one of 2^=8 patterns is available for being displayed at one time period on the screen. Moreover, in case of defining a series of ten patterns as an illumination pattern, the number of illumination patterns is 8^10=1073741824. A lot of illumination patters each of which may include combinations of plural colors are available for displaying on the screen. 
   According to this embodiment, although both the LEDs and the conduit plate are fixed, color spots on the screen are displayed as if the spots revolve around with changing their colors. Therefore, the illumination system improves visual amusement of the portable communication device  1 . 
   The sizes of spots displayed on the screen are different from each other. This difference supplies perspective to the screen. Therefore, in spite of its simple structure, the illumination system of this embodiment provides perspective decoration on the screen. 
   As mentioned above, according to this embodiment, the appearance and amusement of the portable communication device  1  are improved. This improvement depends on the conduit plate between the LEDs and the screen. All of these are fixed elements. Therefore, the Illumination system can be installed into a device without preventing miniaturization, weight saving, reducing the thickness and cost of the device. 
   Description will be made about a second embodiment of the present invention with reference to  FIG. 19 . Compared to the illumination system of the first embodiment, a screen  33 A of the second embodiment corresponding to the screen  33  has another structure. The screen  33 A includes a transparent plate  39  and a white layer  41   a  that covers the exit surface of the transparent plate  39 . The incoming surface of the transparent plate  39  faces the light source unit  31  and the exit surface of the transparent plate  39  faces outside of the portable communication device  1 . 
   In an illumination system including a screen with a white layer on its incoming surface of a transparent plate, light rays focus Images on the white layer and do not travel thorough the transparent plate. On the other hand, in the illumination system including the screen  33 A, light rays travel through the transparent plate  39  and then focus on the white layer  33 A. Therefore, the screen  33 A displays larger images and their movement on the white layer  41   a  than the screen including the white layer on the incoming surface does. As a result, more dynamic movement of spots is displayed on the screen  33 A than on the screen  33 . 
   Description will be made about a third embodiment of the present invention. According to the third embodiment, the illumination system includes a screen  33 B as shown in  FIGS. 20 and 21 . The screen  33 B includes, as shown in  FIG. 20 , a transparent plate  39 , a white layer  41   b  on the exit surface of the plate  39  and another white layer  41   c  on the Incoming surface of the plate  39 . The white layers  41   b  and  41   c  have outlines and are arranged so as not to overlap with each other, or so that light rays are cast on one of the white layer  41   b  and  41   c . For example, in case of  FIG. 21 , the white layer  41   b  Is star-shaped and the white layer  41   c  has a star-shaped hole, which corresponds to the shape of the white layer  41   b , at its center. 
   According to this embodiment, since there is a light path difference between the white layers  41   b  and  41   c , stereoscopic effect is provided. Further, a desired shape, in this embodiment a star-shape is desired, can be illuminated on the white layer  41   b.    
   While this invention has thus far been described in conjunction with a few embodiments thereof, it will be readily possible for those skilled in the art to put the this invention into various other manners. 
   Although the illumination system is installed in order for example to inform of receiving a call, it may be installed to light up key buttons of the portable communication device  1 . 
   In the embodiments mentioned above, in response both to receiving a call and to establishing a connection, the illumination system works according to a single illumination pattern. However, different illumination patterns may be applied. 
   In the embodiments mentioned above, the upper and lower illuminators  5  and  6  synchronously blinks according to the same blinking pattern. However, each of the upper and lower illuminators  5  and  6  may asynchronously blink according to a single blinking pattern, may synchronously blink a different blinking pattern from each other, or may independently blink according to a different blinking pattern. 
   The number of illuminators is not necessarily 2. The number may be one or more than 3. 
   In the embodiments the red, green and blue LEDs are arranged in a triangle. However, the LEDs may be arranged in a single line. 
   The numbers of the red, green and blue LEDs may be not only one but also more than two. The numbers may be different from each other. For example, the numbers of the red, green and blue LEDs may be one, two and three, respectively. 
   In the embodiments, the combination of colors of the LEDs is red, green and blue to constitute an additive color system. However, according to the present invention, color combination of the LEDs are not restricted to an additive color system. For example, a combination of orange, yellow and yellowish green LEDs may compose the light source unit. Further, a white LED may be added to the combinations. 
   A combination of cyan, magenta and yellow lights may be emitted from the light source unit. These emissions may be made by a combination of cyan, magenta and yellow LEDs to constitute an additive secondary color system. A color of the additive secondary color system may be emitted from a combination of a LED which emits a color of an additive color system and a fluorescent plate which emits another color of the additive color system. Alternatively, as shown in  FIG. 22 , a color of the additive secondary color system may be emitted from a combination of a white LED  50  and a color filter  51 . 
   In the embodiments, the LEDs are just switched between ON and OFF and their emission intensities are not variable. However, according to the present invention, the emission intensities may be variable to change the amount of light through the penetrable area. In this case, the illumination system can provide richer expressiveness than the illumination system mentioned above can. 
   In the embodiments, the auxiliary display is a LCD. However, the auxiliary display may be composed of LEDs. Further, when the auxiliary display is composed of LEDs, they may include the LEDs of the upper and lower illuminations. 
   In the embodiment, the blinking pattern is fixed. However, the blinking pattern may be settable by the operator of the portable communication device. In this case, the operator previously sets a desired blinking pattern to the memory  4 . The controller  3  accesses the memory  4  to read the setting of the blinking pattern and orders the LED driver  7  to drive the LEDs of the upper and lower illuminators  5  and  6  according to the blinking pattern. In this case, the present invention can provide fun to adjust a blinking pattern to the operator of the portable communication device. 
   Each of the penetrable areas on the conduit plate may have any shape. For example, a penetrable area may be a circle, triangle, rectangle, star-shaped, or even Indeterminate form. Further, the penetrable areas may be arranged in any formation. For example, the penetrable areas are arranged in a grid, radiation spiral or irregular pattern. The conduit plate may be composed of a net member woven from line members In a grid pattern, or of a pectinate member woven from line members that are arranged in parallel with each other. 
   Although in the embodiments the illumination system includes a single conduit plate, the illumination system of the present invention may include plural conduit plates. In this case, penetrable areas on one conduit plate may be or not be arranged at the same positions where penetrable areas on other conduit plate are arranged. 
   A transparent plate on which a black layer is formed as opaque areas may be used as the conduit plate. For example, the black layer may be printed on the transparent plate to form opaque areas. 
   Instead of a white layer on the screen, a diffusion layer may be formed on the screen. The surface of the diffusion layer is unevenness in order to diffuse incoming light and is for example a satin finished surface or a wrinkle surface. 
   The conduit plate  32  and screen  33  as illustrated in  FIG. 23  and represented by reference no.  52 , may be detachable from the illumination system  53  included the light source unit  31 . At least one of the conduit plate and the screen may be adjustable to adjust the space between them. 
   In the abovementioned embodiments, the conduit plate, screen and white layer are flat. Instead, they may be domed. 
   The conduit plate  32  may be integrated with the lower surface  54  of the screen  33  as shown in  FIG. 24 . 
   Inside of the upper housing  21  covering the upper and lower Illuminators may be painted white or silver. 
   In the third embodiment, a single star-shaped white layer  41   b  is formed on the center of the transparent plate  39 . However, plural shapes may be formed on the transparent plate  39 . The plural shapes may be arranged in for example concentric circles, stripes or a checkerboard pattern.