JP2011112903A - Display device, portable electronic equipment, portable communication terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device where a display panel is hard to be broken even if a load is applied from the outside. <P>SOLUTION: The display device includes a casing 40, a liquid crystal display panel 41 supported by the casing 40, and a screen 42 supported by the casing 40 on the opposite side to the housing 40 with respect to the liquid crystal display panel 41. The casing 40 is made of high rigidity plastic with a Young's modulus of 10,000 MPa or more. The liquid crystal display panel 41 is supported by the casing 40 via an elastic body 49. The thickness of the liquid crystal display panel 41 is set at 0.5 mm. Both of the gap g1 between the liquid crystal display panel 41 and the screen 42 and the gap g2 between the liquid crystal display panel 41 and the casing 40 are set at 0.5 mm. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a display device, a portable electronic device, and a portable communication terminal.

  As this type of technology, Patent Document 1 discloses a display device having a configuration in which a liquid crystal panel is sandwiched between a display plate and a casing member. In this display device, an elastic member is installed between the liquid crystal panel and the display plate, and in addition, between the liquid crystal panel and the casing member, so that the liquid crystal panel is damaged even when a strong impact is applied from the outside. It has become difficult. In particular, the elastic member is formed without interruption so as to surround the display area of the liquid crystal panel, and a function as a so-called air damper is realized.

  In said patent document 1, it is said that the said housing member is desirably formed with an inelastic body, for example, a plastic, a metal, glass, ceramics etc. are illustrated.

JP-A-9-73072

  By the way, in a general display device, a plastic having a Young's modulus of approximately 2000 to 3000 MPa is employed as the above-described casing member. This is because the higher the Young's modulus, the stronger the warpage after molding, resulting in a decrease in yield. As is well known, plastics having a Young's modulus of about 2000 to 3000 MPa are extremely inexpensive due to the mass production effect, and it cannot be overlooked that they are extremely advantageous in recent price competition.

  However, in the field of portable electronic devices in recent years, not only competition in terms of functions and performance but also intense competition has been developed for the design and thinning of terminals themselves. In particular, regarding the thinning of the housing itself, an important development theme is how to make it compatible with the protection of the liquid crystal panel from external loads.

  The present invention has been made in view of the above circumstances, and a main object thereof is to provide a display device in which a display panel is hardly damaged even when a load is applied from the outside.

  According to an aspect of the present invention, a display device configured as follows is provided. That is, the display device includes a housing, a display panel supported by the housing, and a display plate supported by the housing on the opposite side across the housing and the display panel. The casing is made of a highly rigid plastic having a Young's modulus of 10,000 MPa or more.

  According to the present invention, it is possible to provide a display device in which the display panel is hardly damaged even when a load is applied from the outside.

Sectional drawing of the liquid crystal display device which concerns on 1st embodiment External perspective view of a foldable mobile phone provided with a liquid crystal display device according to the second embodiment III-III sectional view of FIG. Sectional view taken along line IV-IV in FIG. It is a figure similar to FIG. 4, Comprising: The figure which shows a modification

<First embodiment>
Hereinafter, a first embodiment of the present invention will be described with reference to FIG. In the present embodiment, a portable communication terminal is taken as an example of a portable electronic device. A mobile phone is taken up as an example of a mobile communication terminal. FIG. 1 shows a cross section of the display device 3 of the mobile phone 1 according to the present embodiment.

  The display device 3 according to the present embodiment is supported by the housing 40, a liquid crystal display panel 41 as a display panel supported by the housing 40, and the opposite side of the housing 40 and the liquid crystal display panel 41. And a screen 42 as a display board. And in said embodiment, said housing 40 is formed with the highly rigid plastic whose Young's modulus is 10,000 Mpa or more. In this specification, the Young's modulus of each material is measured by JIS K7203 (hard plastic bending test method).

  The liquid crystal display panel 41 includes an upper glass 43 as a first transparent electrode and a lower glass 44 as a second transparent electrode. The upper glass 43 and the lower glass 44 face each other in parallel. A transparent electrode is formed on the surface of the upper glass 43 facing the lower glass 44. Similarly, a transparent electrode is formed on the surface of the lower glass 44 facing the upper glass 43. Liquid crystal is sealed between the upper glass 43 and the lower glass 44, and a liquid crystal layer is formed by the sealed liquid crystal. A polarizing film is attached to the outer surface of the liquid crystal display panel 41. Further, the lower glass 44 is longer in the left-right direction in FIG. 1 than the upper glass 43, and controls the display of the display device 3 in a portion of the lower glass 44 that does not face the upper glass 43. A controller LSI 45 is formed.

  The screen 42 is made of tempered glass in the present embodiment. For example, the tempered glass is obtained by heating a plate glass to about 700 ° C. and then spraying air on the surface of the glass to uniformly cool it to form a compression layer on the surface side.

  As described above, the casing 40 is formed of a high-rigidity plastic having a Young's modulus of 10,000 MPa or more in the present embodiment. Examples of the high-rigidity plastic include polyacetal resin, polyamide MXD6 resin, and polybutylene terephthalate resin. As described above, a high-rigidity plastic having an extremely high Young's modulus is considered to be completely unsuitable for the casing of the mobile phone 1 according to current common general knowledge. This is due to the following reason. That is, the plastic generally used as the casing of the mobile phone 1 is a plastic having a Young's modulus of about 2000 to 3000 MPa. Examples of such low-rigidity plastics include polycarbonate resin, ABS resin, and acrylic resin. The reason why the low-stiffness plastics listed here are adopted is that the higher the Young's modulus, the stronger the warpage after the molding process, resulting in a decrease in yield. For example, if the yield of the low-rigidity plastic is 1, the yield of the high-rigidity plastic is generally 0.6 to 0.7. Further, as is well known, plastics having Young's modulus of about 2000 to 3000 MPa are extremely inexpensive, and it cannot be overlooked that they are extremely advantageous in recent price competition. Therefore, it can be said that the high-rigidity plastic having an extremely high Young's modulus as described above is completely unsuitable for the casing of the mobile phone 1.

  On the other hand, the inventor of the present application is able to obtain the following excellent technical characteristics by adopting the above-mentioned high-rigidity plastic which is deliberately disadvantaged while accepting the above disadvantages after earnest research. I found it.

  First, the inventor of the present application performed a drop impact test in which the cellular phone 1 was dropped from a predetermined height onto a concrete test floor in an appropriate posture, and the resistance against the impact of the housing 40 was tested. As the predetermined height, 1.0 m, 1.1 m, 1.2 m,... 1.8 m, 1.9 m, and 2.0 m were prepared. Then, the height at which the cellular phone 1 was dropped was increased in order of 0.1 m in order, and the dropped height when the case 40 was broken such as a crack was recorded. As the material of the casing 40, polyamide MXD6 resin (Young's modulus = 14,000 MPa) was used as the high-rigidity plastic, and polycarbonate resin (Young's modulus = 2,600 MPa) was used as the low-rigidity plastic. The material of the screen 42 at this time was not tempered glass but acrylic having a Young's modulus of about 3,000 MPa. According to this test, when a low-rigidity plastic is used as the casing 40, the casing 40 is damaged just by dropping the mobile phone 1 from a height of 1.2 m, whereas a high-rigidity plastic is used. Even when the mobile phone 1 was dropped from a height of 1.5 m, the housing 40 was not damaged. That is, when a high-rigidity plastic was used as the housing 40, the drop impact test was approximately 1.25 times as good as that obtained when a low-rigidity plastic was used. Note that 1.5 m is the maximum height at which an adult male is assumed to drop the mobile phone 1.

  Secondly, the present inventor applied a predetermined load to the display device 3 of the mobile phone 1 perpendicularly to the housing 40 and performed a load resistance test to test the load resistance of the housing 40. As the predetermined load, 100N, 200N, 300N, 400N, 500N, and 600N were prepared. Then, the load applied to the display device 3 of the mobile phone 1 was increased in order of 100 N, and the load when the liquid crystal display panel 41 was cracked was recorded. The material of the housing 40 and the screen 42 is the same as that in the drop impact test. According to this test, when a low-rigidity plastic is used as the casing 40, the liquid crystal display panel 41 is cracked only by applying a load of 300 N to the display device 3 of the mobile phone 1. When rigid plastic was used, the liquid crystal display panel 41 did not crack at all even when a load of 500 N was applied to the display device 3 of the mobile phone 1. Note that 500 N is the maximum load that an adult male is assumed to apply to the display device 3 of the mobile phone 1.

  As described above, the inventor of the present application has adopted a high-rigidity plastic having a Young's modulus of 10000 MPa or more as the housing 40 in a manner contrary to the current technical common sense. It is possible to provide a display device in which the liquid crystal display panel 41 is less likely to be damaged even if the above is added. The above-mentioned adoption completely deviates from the current common sense technology direction, and there is an intrinsic value of the above-mentioned adoption.

  Note that the upper limit value of the Young's modulus of the high-rigidity plastic used as the housing 40 is approximately 15,000 MPa if it is set by paying attention only to the cost.

<Second embodiment>
Next, a second embodiment of the present invention will be described. The present embodiment includes all the technical features of the first embodiment. In principle, constituent elements corresponding to the constituent elements of the first embodiment are denoted by the same reference numerals. The description will focus on the differences from the first embodiment, and overlapping descriptions will be omitted as appropriate.

  As shown in FIG. 2, the mobile phone 1 (portable electronic device, mobile communication terminal) includes an operation device 2 and a display device 3. The controller device 2 includes an operation button group 7 and a voice input unit 8 to which a voice uttered by a user of the mobile phone 1 is input on the front side 4. The operation button group 7 includes a function setting operation button 9 for operating various functions such as various settings, a phone book function, and a mail function, and an input operation button 10 for inputting a telephone number and characters such as mail. And a determination operation button 11 for performing determination and scrolling in various operations. An earphone connection portion 14 and an external connection portion 15 are provided on one side surface 13 of the operating device 2, and these connection portions 14 and 15 are covered with caps 16 and 17 that can be opened and closed, respectively. The display device 3 has a main display surface 26 for displaying various information on the surface side 25 facing the surface side 4 of the controller device 2 when closed, and an audio output unit 27 for outputting the voice of the other party of the call. . The operating device 2 and the display device 3 are connected via a hinge mechanism 35. The mobile phone 1 moves the operating device 2 and the display device 3 open relative to each other or folded by relatively moving the operating device 2 and the display device 3 connected via the hinge mechanism 35. It is possible to make a state.

  As shown in FIG. 3, the display device 3 according to this embodiment includes a housing 40, a liquid crystal display panel 41 as a display panel supported by the housing 40, and the opposite side across the housing 40 and the liquid crystal display panel 41. And a screen 42 as a display board supported by the housing 40. The casing 40 includes a panel support plate 46 as a first support plate facing the liquid crystal display panel 41, and an outer frame as a second support plate provided on the opposite side across the liquid crystal display panel 41 and the panel support plate 46. 47. The panel support plate 46 is fixed to the outer frame 47 at a position (not shown), and the panel support plate 46 and the outer frame 47 are arranged with a predetermined gap G therebetween. A side wall 48 is formed in an annular shape at the outer edge of the outer frame 47 so as to surround the outer frame 47, and the screen 42 is bonded and fixed to the side wall 48. That is, in this embodiment, the housing 40 is formed in an annular shape so as to surround the outer frame 47, the panel support plate 46 that is disposed with a gap G from the outer frame 47, and the outer frame 47. And a side wall 48. In this configuration, the liquid crystal display panel 41 supported by the housing 40 is specifically supported by the panel support plate 46 of the housing 40.

  In this embodiment, the screen 42 is tempered glass (high rigidity material), and its Young's modulus is 70000 MPa or more. Thus, the following effects are acquired by making the screen 42 very rigid. That is, since both the liquid crystal display panels 41 are sandwiched between the highly rigid housing 40 and the screen 42, even if a load is applied from the outside, the load is received with almost no deformation of the housing 40 or the screen 42. Therefore, deformation of the liquid crystal display panel 41 can be effectively suppressed. Note that the upper limit of the Young's modulus of the tempered glass employed as the screen 42 is set to about 80,000 MPa if it is set by paying attention only to the cost.

  The liquid crystal display panel 41 is supported on the panel support plate 46 of the housing 40 via an elastic body 49. The presence of the elastic body 49 makes it difficult for an externally applied impact to propagate to the liquid crystal display panel 41, so that the liquid crystal display panel 41 is less likely to be damaged by an externally applied impact.

  As the elastic body 49, for example, natural rubber, styrene rubber, nitrile rubber, chlorobrene rubber, butyl rubber, maltoprene rubber, silicone rubber and the like can be used. Among these, silicone rubber is particularly preferable from the viewpoints of temperature stability and manufacturability.

  In the present embodiment, the liquid crystal display panel 41 is formed in a substantially rectangular shape as shown in FIG. Specifically, both the upper glass 43 and the lower glass 44 are formed in a substantially rectangular shape. The elastic body 49 is disposed at the four corners 41 a of the liquid crystal display panel 41. More specifically, the elastic body 49 is disposed at the four corners 41 a in the overlapping region 41 </ b> D where the upper glass 43 and the lower glass 44 overlap in the liquid crystal display panel 41. According to the above configuration, unlike the above-described Patent Document 1, since the elastic body 49 is discontinuously arranged, the elastic body 49 is easily deformed accordingly, and thus an externally applied impact is applied to the liquid crystal display. It becomes more difficult to propagate to the panel 41. The projected area of the elastic body 49 shown in FIG. 4 is preferably as small as possible from the viewpoint of preventing impact propagation.

  In the present embodiment, the elastic body 49 is disposed only at the four corners 41a of the liquid crystal display panel 41 as shown in FIG. 4, but may be additionally disposed at other positions. Instead of the portion 41a, it may be arranged at another position. When the elastic body 49 is disposed only at the four corners 41a of the liquid crystal display panel 41 as shown in FIG. 4, the support area of the liquid crystal display panel 41 by the elastic body 49 becomes extremely small. There is an effect that the impact is more difficult to propagate to the liquid crystal display panel 41.

  On the other hand, when the liquid crystal display panel 41 has the long side 50 and the short side 51 as shown in FIG. 4, the elastic body 49 is arranged at the center of the long side 50 of the liquid crystal display panel 41 as shown in FIG. 5. You may arrange further in each of neighborhood. According to the above configuration, the housing 40 can support the liquid crystal display panel 41 in a more balanced manner. In addition, when the number of the elastic bodies 49 to be installed is increased, there is a merit that bending of the liquid crystal display panel 41 is suppressed, but there is a demerit that an externally applied impact is easily transmitted to the liquid crystal display panel 41. The number of elastic bodies 49 to be installed may be determined as appropriate by comparing the advantages and disadvantages.

  As shown in FIG. 4, the elastic body 49 is preferably formed in a substantially circular shape when viewed from the normal direction of the liquid crystal display panel 41. This is because it is possible to suppress the occurrence of stress concentration on the liquid crystal display panel 41 at the outer edge of the elastic body 49 when an impact is applied from the outside.

  In FIG. 3, the elastic body 49 is bonded to the liquid crystal display panel 41 and the panel support plate 46 of the housing 40 using an adhesive such as a silicone rubber adhesive.

  In the present embodiment, the thickness of the liquid crystal display panel 41 is set to 0.5 mm. Here, the thickness of the liquid crystal display panel 41 means the sum of the thickness of the upper glass 43 and the thickness of the lower glass 44. Thus, when the thickness of the liquid crystal display panel 41 is set to 0.5 mm, the absolute proof stress is reduced as compared with the case where the thickness is generally set (0.8 to 1.2 mm). End up. While accepting such technical disadvantages, by setting the thickness of the liquid crystal display panel 41 to 0.5 mm as described above, the tensile stress generated outside the deflection when the liquid crystal display panel 41 is bent. Can be strongly suppressed, and on the contrary, the liquid crystal display panel 41 can be prevented from being damaged.

  The gap g1 between the liquid crystal display panel 41 and the screen 42 and the gap g2 between the liquid crystal display panel 41 and the panel support plate 46 of the housing 40 are both set to 0.5 mm. According to the above settings, when an impact is applied from the outside, the liquid crystal display panel 41 comes into contact with the screen 42 or the panel support plate 46 of the housing 40 with only slight deflection. That is, a strong restriction is imposed on the bending of the liquid crystal display panel 41 when an impact occurs. And this powerful restriction contributes to prevention of breakage of the liquid crystal display panel 41. In particular, the inventor of the present application has conducted a bending test of the liquid crystal display panel 41 having a thickness set to 0.5 mm, and ascertains that the liquid crystal display panel 41 starts to break when the deflection becomes about 2 mm. Therefore, it can be said that the setting of the gap g1 and the gap g2 is extremely reasonable considering the result of the bending test and a slight margin. The gaps g1 and g2 are measured at the panel center of the liquid crystal display panel 41. This is because the center of the panel is the most bent part.

  As shown in FIG. 3, a drive circuit 60 for driving the display device 3 is accommodated in the gap G between the panel support plate 46 and the outer frame 47 described above. That is, the housing 40 is constituted by the panel support plate 46 and the outer frame 47, the panel support plate 46 is fixed to the outer frame 47, and the panel support plate 46 and the outer frame 47 are arranged with a predetermined gap G therebetween. By doing so, the following effects can be obtained. That is, while the liquid crystal display panel 41 is supported by the housing 40, the drive circuit 60 for driving the liquid crystal display panel 41 can be accommodated on the opposite side of the screen 42 and the liquid crystal display panel 41 without any problem. become. The drive circuit 60 and the controller LSI 45 are connected by a flexible wiring (not shown).

  The embodiments described above are summarized as follows from a different viewpoint.

(1) The display device 3 according to the embodiment includes a housing 40, a liquid crystal display panel 41 supported by the housing 40, and a screen 42 supported by the housing 40 on the opposite side of the housing 40 and the liquid crystal display panel 41. And comprising. The casing 40 is made of a highly rigid plastic having a Young's modulus of 10,000 MPa or more. The screen 42 is made of a highly rigid material having a Young's modulus of 70000 MPa or more. According to the above configuration, it is possible to provide the display device 3 in which the liquid crystal display panel 41 is hardly damaged even when a load is applied from the outside. The above configuration is particularly advantageous in that the liquid crystal display panel 41 can be prevented from being deformed against a static load generated when a heavy object such as a human body or a luggage is placed on the display device 3.

(2) Further, the liquid crystal display panel 41 is supported by the housing 40 via the elastic body 49. The liquid crystal display panel 41 has a substantially rectangular shape. The elastic body 49 is disposed only at the four corners 41 a of the liquid crystal display panel 41. According to the above configuration, since a dynamic impact applied from the outside is difficult to propagate to the liquid crystal display panel 41, the liquid crystal display panel 41 is hardly damaged.

(3) The liquid crystal display panel 41 is set to a thickness of 0.5 mm. Both the gap g1 between the liquid crystal display panel 41 and the screen 42 and the gap g2 between the liquid crystal display panel 41 and the housing 40 are set to 0.5 mm. According to the above configuration, the liquid crystal display panel 41 can be prevented from being greatly deformed by the inertial force of a dynamic impact applied from the outside. Even if the liquid crystal display panel 41 is deformed, the liquid crystal display panel 41 is not deformed. The generated tensile stress can be strongly reduced.

  The preferred embodiments of the present invention have been described above. In each of the above embodiments, a mobile communication terminal is taken up as an example of a portable electronic device, and a mobile phone is taken up as an example of a mobile communication terminal. Needless to say, the present invention can be applied not only to portable communication terminals but also to portable information processing devices and other portable electronic devices as portable electronic devices. Examples of the portable information processing apparatus include a PDA (Personal Digital Assistant) and a notebook personal computer. Examples of the mobile communication terminal include a mobile phone and a PHS (Personal Handy-phone System). Examples of other portable electronic devices include portable music players, portable game machines, digital cameras, and digital video cameras.

DESCRIPTION OF SYMBOLS 1 Cellular phone 2 Operating device 3 Display device 40 Housing 41 Liquid crystal display panel (display panel)
42 screen (display board)

Claims (21)

The body,
A display panel supported by the housing;
A display plate supported by the housing on the opposite side across the housing and the display panel;
With
The casing is formed of a high-rigidity plastic having a Young's modulus of 10,000 MPa or more.
Display device. The display device according to claim 1,
The display board is made of a highly rigid material having a Young's modulus of 70000 MPa or more.
Display device. The display device according to claim 2,
The display board is tempered glass,
Display device. The display device according to any one of claims 1 to 3,
The display panel is supported by the housing via an elastic body,
Display device. The display device according to claim 4,
The display panel has a substantially rectangular shape,
The elastic body is disposed at least at four corners of the display panel,
Display device. The display device according to claim 5,
The elastic body is disposed only at four corners of the display panel.
Display device. The display device according to claim 5,
The display panel has a long side and a short side,
The elastic body is further disposed in the vicinity of the center of the long side of the display panel,
Display device. A display device according to any one of claims 4 to 7,
The elastic body is formed in a substantially circular shape when viewed from the normal direction of the display panel.
Display device. A display device according to any one of claims 4 to 8,
The elastic body is bonded to the display panel and the housing;
Display device. A display device according to any one of claims 4 to 9,
The elastic body is formed of any of natural rubber, styrene rubber, nitrile rubber, chlorobrene rubber, butyl rubber, maltoprene rubber, and silicone rubber.
Display device. A display device according to any one of claims 1 to 10,
The display panel is set to a thickness of 0.5 mm.
Display device. A display device according to any one of claims 1 to 11,
Both the gap between the display panel and the display plate and the gap between the display panel and the housing are set to 0.5 mm.
Display device. A display device according to any one of claims 1 to 12,
The housing includes a first support plate facing the display panel, and a second support plate provided on the opposite side across the display panel and the first support plate,
The first support plate is fixed to the second support plate with a predetermined gap;
Display device. A display device according to any one of claims 1 to 13,
The display panel is a liquid crystal display panel;
Display device. A mobile communication terminal comprising the display device according to claim 1. A portable electronic device comprising the display device according to claim 1. The body,
A display panel supported by the housing;
A display plate supported by the housing on the opposite side across the housing and the display panel;
With
The casing is formed of a high-rigidity plastic having a Young's modulus of 10,000 MPa or more,
The display board is made of a highly rigid material having a Young's modulus of 70000 MPa or more.
Display device. The display device according to claim 17,
The display panel is supported by the housing via an elastic body,
The display panel has a substantially rectangular shape,
The elastic body is disposed only at four corners of the display panel.
Display device. The display device according to claim 17 or 18,
The display panel has a thickness set to 0.5 mm,
Both the gap between the display panel and the display plate and the gap between the display panel and the casing are set to 0.5 mm.
Display device. A mobile communication terminal comprising the display device according to claim 17. A portable electronic device comprising the display device according to claim 17.

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