`Application Publication No. 5-69732
`(43) Publication Date: September 21, 1993
`(21) Application No. 4-7110
`(22) Application Date: February 20, 1992
`(71) Applicant: Toshiba Corporation
`(71) Applicant: Toshiba AVE Corporation
`(72) Inventor: Koichi SERAKU
`(74) Agent: Patent Attorney, Takashi HONDA
`(54) [Title of Device] BACKLIGHT STRUCTURE FOR LIQUID
`CRYSTAL DISPLAY
`(57) [ABSTRACT]
`[Object] To provide a backlight structure for a liquid
`crystal display which can illuminate the liquid crystal
`display from a back surface side thereof without increasing
`the size of a mounting space for the liquid crystal display.
`[Construction] Light sources 13 are provided at both ends
`of a second glass substrate 11b of a liquid crystal display
`11 having first and second glass substrates, and a light
`reflecting layer 18 is provided on a surface of the second
`glass substrate 11b opposite to the first glass substrate
`11a by the intermediary of a light diffusing layer 17.
`[CLAIM]
`[Claim 1] A backlight structure for a liquid crystal
`display including a first glass substrate, a second glass
`
`- 1 -
`
`Sony Corp. Exhibit 1029
`
`SONY_000887
`
`
`
`substrate and liquid crystal disposed therebetween,
`configured to irradiate light from the second glass
`substrate side toward the first glass substrate side,
`comprising: light sources provided at both ends of the
`second substrate and configured to irradiate light toward
`the second glass substrate; and a reflecting layer
`configured to reflect light and provided on a surface of the
`second glass substrate opposite to a surface on which the
`liquid crystal is arranged with a diffusing layer configured
`to diffuse light interposed therebetween.
`[Brief Description of the Drawings]
`
`[Fig. 1] Fig. 1 is a cross-sectional view taken along
`the line A-A in Fig. 2 in a state in which a liquid crystal
`display is mounted.
`
`[Fig. 2] Fig. 2 is an exploded perspective view for
`explaining a backlight structure for the liquid crystal
`display of the first example of the present invention.
`
`[Fig. 3] Fig. 3 is an exploded perspective view
`illustrating a mounting structure for a liquid crystal
`display of the related art.
`
`[Fig. 4] Fig. 4 is an exploded perspective view of a
`backlight unit of the related art.
`
`[Fig. 5] Fig. 5 is a cross-sectional view taken along
`the line B-B in Fig. 3 in a state in which the liquid
`crystal display is mounted.
`
`- 2 -
`
`SONY_000888
`
`
`
`[Reference Numerals]
`11
`liquid crystal display
`11a first glass substrate
`11b second glass substrate
`11c liquid crystal
`13
`light source
`18
`reflecting layer
`17
`diffusing layer
`
`[Detailed Description of the Device]
`[0001]
` [Field of Industrial Application]
`
`The present invention relates to a backlight structure
`configured to illuminate a liquid crystal display from a
`back surface side thereof.
`[0002]
` [Description of the Related Art]
`
`A mounting structure for a liquid crystal display of
`the related art is illustrated in Fig. 3 to Fig. 5.
`[0003]
`
`Mounting of a liquid crystal display (LCD) 1 is
`performed as illustrated in Fig. 3 by fitting the LCD 1 in a
`holding frame 2, positioning a rubber connector 3 and a
`backlight unit 4 on a back surface side of the LCD 1,
`inserting mounting legs 2a of the holding frame 2 into
`
`- 3 -
`
`SONY_000889
`
`
`
`square holes 6a of a printed wiring board 6, and twisting
`distal ends of the mounting legs 2a on a back surface side
`of the printed wiring board 6. Accordingly, the LCD 1 is
`fixed to the printed wiring board 6, and is electrically
`connected to the printed wiring board 6 via the rubber
`connector 3.
`[0004]
`
`In contrast, the backlight unit 4 includes a light
`guide panel 8, LEDs 9, 9 to be positioned at both end
`surfaces of the light guide panel 8, and a reflecting case
`10 to which the light guide panel 8 and the LEDs 9, 9 are
`fitted as illustrated in Fig. 4, is positioned on the back
`surface side of the LCD 1 when mounting the LCD 1 on the
`printed wiring board 6, and terminals 9a of the LEDs 9 are
`soldered to the printed wiring board 6. Therefore, as
`illustrated in Fig. 5, light irradiated from the LEDS 9 is
`guided to the light guide panel 8, and is reflected by the
`reflecting case 10, thereby irradiating the back surface
`side of the LCD 1. In this case, the reflecting case 10 is
`formed of a white material so as to reflect light
`efficiently, and a back surface 8a of the light guide panel
`8 is formed to have uneven surface so as to diffuse light.
`Therefore, the back surface side of the LCD 1 is irradiated
`with light of the LEDs 9 uniformly.
`[0005]
`
`- 4 -
`
`SONY_000890
`
`
`
`According to the structure of the related art, the
`
`light guide panel 8 configured to guide light of the LEDs 9
`is required as a backlight structure that illuminates the
`LCD 1, and the light guide panel 8 needs to guide light
`irradiated from the LEDs 9 efficiently. Therefore, the
`thickness thereof cannot be reduced to a thickness smaller
`than that of the LEDs 9. Therefore, the height of the LED 1
`from the printed wiring board 6 is increased, and hence a
`problem of an increase of a space required for mounting the
`LED 1 arises.
`[0006]
` [Problem to be Solved by the Device]
`
`As described above, in the back light structure of the
`liquid crystal display of the related art, since there is a
`need to provide the light guide panel for guiding light from
`the light sources on a bottom surface side of the liquid
`crystal display, and hence a problem that the mounting space
`for the liquid crystal display is increased correspondingly
`arises.
`[0007]
`
`The present invention is intended to solve the
`problems of the related art, and intended to provide a
`backlight structure for a liquid crystal display in which
`the liquid crystal display can be illuminated without
`increasing a mounting space for the liquid crystal display.
`
`- 5 -
`
`SONY_000891
`
`
`
`[0008]
` [Means for Solving the Problem]
`
`In the present invention, in a backlight structure for
`a liquid crystal display including a first glass substrate,
`a second glass substrate and liquid crystal disposed
`therebetween, configured to irradiate light from the second
`glass substrate side toward the first glass substrate side,
`comprising: light sources provided at both ends of the
`second substrate and configured to irradiate light toward
`the second glass substrate; and a reflecting layer
`configured to reflect light and provided on a surface of the
`second glass substrate opposite to a surface on which the
`liquid crystal is arranged with a diffusing layer configured
`to diffuse light interposed therebetween.
`[0009]
` [Operations]
`
`In the present invention, light irradiated from light
`sources is guided by the second substrate, is diffused by
`the diffusing film arranged on a back surface side of the
`second substrate, and is reflected by a reflecting film.
`Therefore, a liquid crystal display is uniformly irradiated
`with the light from the light sources from the back surface
`side.
`[0010]
`[Example]
`
`- 6 -
`
`SONY_000892
`
`
`
`Referring now to Fig. 1 and Fig. 2, an example of the
`
`present invention will be described.
`[0011]
`
`Fig. 2 is an exploded perspective view for explaining
`a mounting structure for a liquid crystal display, and Fig.
`1 is a cross-sectional view taken along the line A-A in Fig.
`2 in a state in which the liquid crystal display is mounted.
`[0012]
`
`Mounting of a liquid crystal display (LCD) 11 is
`performed as illustrated in Fig. 2 by fitting the LCD 11
`having LEDs 13, 13 which serve as light sources positioned
`at both ends thereof in a holding frame 14, positioning a
`rubber connector 16, a diffusing film 17, and a reflecting
`film 18 on a back surface side of the LCD 11, inserting
`mounting legs 14a of the holding frame 14 into square holes
`20a of a print wiring board 20, and twisting distal ends of
`the mounting legs 14a on the back surface side of the print
`wiring board 20. Accordingly, the LCD 11 is fixed to the
`printed wiring board 20, and is electrically connected to
`the printed wiring board 20 via the rubber connector 16.
`[0013]
`
`By mounting the LCD 11 on the print wiring board 20 in
`a manner described above, the LEDs 13, 13 illustrated in Fig.
`1 are positioned at the both ends of the LCD 11, and the
`diffusing film 17 and the reflecting film 18 are positioned
`
`- 7 -
`
`SONY_000893
`
`
`
`between the LCD 11 and the print wiring board 20. With
`these components, a backlight structure that illuminates the
`LCD 11 from the back surface side thereof is configured.
`The configuration will be described in detail below.
`[0014]
`
`The LCD 11 includes a first glass substrate 11a which
`is a display surface side, a second glass substrate 11b,
`which is the back surface side, and liquid crystal 11c
`interposed therebetween, the LEDs 13, 13 are positioned at
`both end surfaces of the second glass substrate 11a [sic -
`it seems to be an error in the publication, which should be
`"11b"] of the LCD 11, and terminals 13a are soldered to a
`pattern (which is not illustrated) on the printed wiring
`board 20. Therefore, light irradiated from the LEDs 13 is
`guided into the second glass substrate 11a [sic - it seems
`to be an error in the publication, which should be "11b"].
`[0015]
`
`The diffusing film 17, which is a diffusing layer, is
`in tight contact with the second glass substrate 11a, and
`the reflecting film 18, which is a reflecting layer, is in
`tight contact with the diffusing film 17.
`[0016]
`
`The diffusing film 17 is formed of a transparent thin
`plate, and uneven surface such as frosted glass is formed on
`a surface side that comes into contact with the reflecting
`
`- 8 -
`
`SONY_000894
`
`
`
`film 18. Therefore, light guided by the second glass
`substrate 11a is diffused by the diffusing film 17. The
`reflecting film 18 is formed of a white thin plate to allow
`easy reflection of light. Therefore, light reaching the
`reflecting film 18 is reflected by the reflecting film 18,
`and does not leak outside.
`[0017]
`
`In this configuration, light irradiated by the LEDs 13
`is guided into the second glass substrate 11b, is diffused
`by the diffusing film 17, is reflected by the reflecting
`film 18, and reaches the first glass substrate 11a.
`Therefore, by not using the light guide panel 8 as of the
`related art, the height of the LCD 11 from the print wiring
`board 20 can be reduced and, in addition, the LCD 11 can be
`illuminated uniformly by using the LED 13.
`[0018]
`
`In this example, the reflecting film 18 is used as the
`reflecting layer. However, the surface of the print wiring
`board 20 may be coated in white to use as a reflecting layer,
`for example.
`[0019]
`[Advantages]
`
`In the present invention, as described above, since
`the second glass substrate out of the first and second glass
`substrates is used as a light guide panel to illuminate the
`
`- 9 -
`
`SONY_000895
`
`
`
`liquid crystal display from the back surface side, the
`mounting space for the liquid crystal display can be reduced
`by an amount corresponding to the absence of the light guide
`panel of the related art.
`
`- 10 -
`
`SONY_000896
`
`
`
`LIQUID CRYSTAL DISPLAY
`11
`11a FIRST GLASS SUBSTRATE
`11B SECOND GLASS SUBSTRATE
`11C LIQUID CRYSTAL
`13
`LIGHT SOURCE
`18
`REFLECTING LAYER
`17
`DIFFUSING LAYER
`
`- 11 -
`
`SONY_000897