JP3287670B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus using an electron source, and more particularly, to an image forming apparatus having a thin vacuum vessel panel on which an electron source is mounted.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus using an electron source, two types of electron emitters, a thermionic electron source and a cold cathode electron source, have been known as electron emitting elements.
Among them, cold cathode electron sources include a field emission type (hereinafter abbreviated as FE type), a metal / insulating layer / metal type (hereinafter abbreviated as MIM type), and a surface conduction electron emission element.

[0003] An example of the FE type is WP Dyke &
WW Dolan, "Fielddemissio
n ", Advance in Electron Ph
ysics, 8, 89 (1956) or C.I. A. S
pindt, “Physicalproperties
of thin-film field emiss
ion cathodes with mollybde
nium cones ", J. Appl. Phys.,
47, 5248 (1976).

[0004] An example of the MIM type is CA Mea.
d, "The tunnel-emission am
Plier, J. Appl. Phys., 32, 6
46 (1961) and the like are known.

As an example of the surface conduction electron-emitting device,
E. Elinson, RadioEng. Elec
tron Pys., 10, (1965) and the like.

[0006] The surface conduction electron-emitting device utilizes a phenomenon in which an electron is emitted by passing a current through a small-area thin film formed on a substrate in parallel with the film surface. Devices of this type include those using the SnO ₂ thin film described by Elinson et al. And those using an Au thin film [G. Dittmer: “Thin Solid Fi”
lms ", 9,317 (1972)] , In 2 O 3 / S
nO ₂ thin film [M. Hartwell and
C. G. Fonstad: "IEEE Trans.
ED Conf. ", 519 (1975)], based on a carbon thin film [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1,
22 (1983)].

On the other hand, an image forming apparatus to which the above-described electron-emitting device is applied generally has a vacuum container panel on which one or more electron-emitting devices are mounted and which has display means made of a luminescent substance such as a phosphor. Is housed in an outer box having a predetermined structure. As such an apparatus, for example, a multi-element in which a plurality of surface conduction electron-emitting elements are arranged and a panel configuration including the same are known.

[0008]

However, in the image forming apparatus using the above-mentioned conventional electron-emitting device, the vacuum vessel panel is fixed and accommodated by directly bonding it to the outer box or by fastening. I have. Therefore, when vibration or impact is applied during transportation or use of the image forming apparatus, excessive stress is directly applied to members constituting the vacuum container panel, for example, members such as an electron source and front and back plates, Panel destruction may be caused.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide an image forming apparatus using various electron sources. An object of the present invention is to provide a device in which stress applied to a mounted vacuum vessel panel is reduced and which has excellent durability.

[0010]

According to the present invention, there is provided an image forming apparatus comprising: a vacuum vessel panel having at least one or more electron sources; and a display means for emitting light by irradiation of an electron beam generated from the electron source; and the vacuum vessel panel. And an outer box accommodating the vacuum container panel, wherein the vacuum container panel comprises:
Within the outer box, it is supported by an elastic support member is interposed between the vacuum container panel and the inner surface of the outer box
The vacuum vessel panel has the electron source mounted on one main surface.
Back plate, and front plate having the display means on one main surface
However, the main surfaces are opposed to each other, and a frame member is interposed at the peripheral edge.
And, at any point other than the peripheral portion,
Interposed between the back plate and the front plate
The elastic support portion so as to sandwich the frame member via a face plate.
The material is between the back plate and the inner surface of the outer box and the front
It is arranged between the face plate and the inner surface of the outer box .

Further, the image forming apparatus of the present invention has at least
And at least one electron source and an electron beam generated by the electron source.
Vacuum container panel having display means for emitting light by irradiation
And an outer box containing the vacuum container panel
The forming apparatus, wherein the vacuum container panel is inside the outer box.
In the method, an intervening member is provided between the vacuum container panel and the inner surface of the outer box.
It is supported by an elastic support member that has the elastic supporting
The holding member is a spring structure, and is arranged in parallel with the spring structure.
Characterized by having damping means for said mounted spring.
And

In the image forming apparatus of the present invention, a phosphor can be most preferably used as the electron source, using the above-mentioned surface conduction electron-emitting device as a light emitting means.

[0013]

In the image forming apparatus of the present invention, the vacuum container panel is accommodated in the outer case in a state supported by the elastic support member. Therefore, when an external shock or vibration is applied to the image forming apparatus, these are absorbed by the elastic supporting member, and the members constituting the vacuum vessel panel, particularly the electron source, the back plate on which the electron source is mounted, and the image are formed. The stress applied to the front panel or the like to be displayed is significantly reduced. As a result, erroneous operation and destruction of the device are prevented.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. These examples are described for the purpose of facilitating understanding of the present invention, and do not particularly limit the present invention.

FIG. 1 is a schematic view showing the structure of an image forming apparatus according to a first embodiment of the present invention. FIG. 1A is a plan view of the image forming apparatus as viewed from above, and FIG. AA ′ of (a)
It is sectional drawing along the line.

In the image forming apparatus 1 shown in FIG. 1, a vacuum container panel 11 is accommodated in an outer box 12 while being supported by an elastic support member 13.

The vacuum vessel panel 11 has a front plate 14 and a rear plate 15 which are provided at their peripheral edges via a frame member 16 and at any point other than the peripheral edges via columns 17 to prevent destruction by atmospheric pressure. They are arranged facing each other.
Here, the front plate 14 is formed by forming a phosphor and a metal back layer (not shown) as display means on one main surface of a substrate made of a transparent material such as glass. Back plate 1
Reference numeral 5 denotes a structure in which at least one or more electron-emitting devices and driving wires (not shown) are formed as an electron source on one main surface of a substrate made of an insulating material such as glass. Further, an electron-emitting device and a phosphor may be provided on the back plate 15 side at the same time. Such a front plate 14 and a back plate 15
Are bonded to the frame member 16 at the peripheral edge thereof using frit glass via a plurality of columns 17, and the joints are sealed to face each other. Subsequently, the vacuum container panel 11 is formed by removing and sealing the air between the front plate 14 and the back plate 15.

On the other hand, the elastic support member 13 supports the vacuum vessel panel 11 by being interposed between the vacuum vessel panel 11 having the above-described structure and the inner surface of the outer box 12. here,
As shown in FIG. 1B, the elastic support member 13 supports the vacuum container panel 11 so as to support the peripheral portion thereof, that is, to sandwich the frame member 16 via the back plate 14 and the front plate 15. It is preferable that the installation location is not particularly limited.

The elastic support member 16 is not particularly limited as long as it is a member or a structure made of a material exhibiting elasticity. For example, a member or a spring structure made of a rubber material can be used.

FIG. 2 shows a supporting portion (region 18 in FIG. 1B) when an elastic supporting member made of a rubber material is used.
FIG. 4 is a cross-sectional view showing an example of the details. In FIG.
Is a resilient support member made of a rubber material, and recesses 22 and 23 are provided in portions contacting the outer case 12 and the back plate 15, respectively. Correspondingly, convex portions 24 and 25 are formed on the outer box 12 and the back plate 15 side, respectively.
And 23. Thus, the elastic support member 26 made of the rubber material supports the vacuum vessel panel 11 in all directions.

When an elastic supporting member made of a rubber material is used, its shape is not particularly limited to the shape shown in FIG. 2 but depends on the weight of the vacuum vessel panel, the state of use, the ease of manufacture, and the like. Can be selected appropriately. Also,
If necessary, a metal casting or the like may be inserted into the member made of the rubber material.

On the other hand, FIG. 3 is a sectional view showing in detail an example of a support portion (region 18 in FIG. 1B) when a spring structure is used as an elastic support member. In the figure,
Numeral 31 denotes an elastic supporting member made of a disc-shaped spring,
And the convex portion 33 formed on the rear plate 15 are fitted. Thus, the elastic support member 31 made of a dish-shaped spring elastically supports the vacuum container panel 11 mainly in the thickness direction of the device.

When the spring structure is used as the elastic support member, the structure is not particularly limited to the disc-shaped spring shown in FIG.
It can be appropriately selected according to the ease of production and the like. For example, a coiled spring or a torsion bar type spring can be used.

In the image forming apparatus 1 of the first embodiment having the above-described structure, when an impact or vibration is applied from the outside, the impact or vibration is applied to the elastic support member 13, for example, the member 21 made of a rubber material, or the like. The stress applied to the members constituting the vacuum vessel panel 11, particularly the electron source, the back plate 15 on which the electron source is mounted, the front plate 14 for displaying an image, etc., is significantly reduced by being absorbed by the spring structure such as the dish spring 31. Is done. As a result, destruction of the image forming apparatus 1 is prevented, and its durability is improved.

In the image forming apparatus according to the embodiment of the present invention,
In common, a surface conduction electron-emitting device is most preferably used as an electron-emitting device that functions as an electron source mounted on the back plate 15.

Hereinafter, an example of the surface conduction electron-emitting device will be described with reference to FIGS. 4A (plan view) and (b) (B in FIG. 4A).
(A cross-sectional view taken along line -B ')).

2A and 2B, reference numeral 41 denotes an insulating substrate, 45 and 46 denote device electrodes, 44 denotes a thin film including an electron emitting portion, and 43 denotes an electron emitting portion.

Here, the material of the insulating substrate 41 is quartz glass, glass having a reduced content of impurities such as Na, blue plate glass, S plate formed on blue plate glass by sputtering or the like.
Examples include a glass substrate on which iO ₂ is laminated, ceramics such as alumina, and the like.

The material of the device electrodes 45 and 46 facing each other at a predetermined distance may be any material as long as it is a conductive material.
metals or alloys such as r, Au, Mo, W, Pt, Ti, Al, Cu, Pd and Pd, Ag, Au, RuO ₂ , P
Examples include a metal such as d-Ag, or a printed conductor made of a metal oxide and glass, a transparent conductor such as In ₂ O ₃ —SnO ₂ , and a semiconductor conductor material such as polysilicon.

The thin film 44 including the electron-emitting portions provided between the opposing device electrodes 45 and 46 provided on the insulating substrate 41 and on the device electrodes 45 and 46 includes the electron-emitting portion 43. There is also a form in which the cross-sectional shape is not specified as shown in FIG. That is, there is also a mode in which a thin film for forming an electron-emitting portion and device electrodes 45 and 46 facing each other are laminated on the insulating substrate 41 in this order. Further, depending on the manufacturing method, the opposing element electrode 4
There is also a case where the entire area between 5 and 46 functions as an electron emitting portion.

Specific examples of the material constituting the thin film 44 including the electron emitting portion 43 include Pd, Ru, Ag, Au, T
i, In, Cu, Cr, Fe, Zn, Sn, Ta, W,
Metal such as Pb, PdO, SnO ₂ , In ₂ O ₃ , Pb
Oxides such as O and Sb ₂ O ₃ , HfB ₂ , ZrB ₂ , La
Borides such as B ₆ , CeB ₆ , YB ₄ , GdB ₄ , Ti
Carbides such as C, ZrC, HfC, TaC, SiC, WC, nitrides such as TiN, ZrN, HfN, semiconductors such as Si and Ge, carbon, AgMg, NiCu, Pb, Sn
Etc., each of which is composed of fine particles.

The fine particle film described here is a film in which a plurality of fine particles are gathered, and has a fine structure not only in a state where the fine particles are individually dispersed and arranged, but also in a state where the fine particles are adjacent to each other or overlap each other ( (Including islands).

The electron emitting portion 43 is preferably made of a large number of conductive fine particles. The electron emitting portion 43 depends on the thickness of the thin film 44 including the electron emitting portion and the production method such as the energization processing conditions described later.
It is set appropriately. The material forming the electron emitting portion 43 is the same as the material having some or all of the elements of the material forming the thin film 44 including the electron emitting portion 43.

FIGS. 5A and 5B schematically show the structure of an image forming apparatus according to a second embodiment of the present invention. FIG. 5A is a plan view of the apparatus, and FIG. It is sectional drawing along CC '.

The image forming apparatus 5 shown in FIG. 5 has basically the same structure as that of the image forming apparatus of the first embodiment shown in FIG. 1 described above, and has a structure in which a spring structure is used as an elastic supporting member. This is an application example. In FIG. 5, members having the same functions as those of the apparatus of FIG. 1 are denoted by the same reference numerals.

In the device 5, the elastic support member 1
As 3, a coil spring 53 which is a spring structure is used. Further, a damping means (damper) 54 is provided in parallel with the coil spring 53.

Here, the shape and the number of windings of the coil spring 53 are not particularly limited, and can be appropriately selected according to the weight of the vacuum vessel panel, the state of use, the ease of manufacture, and the like. On the other hand, as the damping means 54, for example,
An oil damper, an air damper, or a silicon-based gel-like substance can be used.

FIG. 6 is a sectional view showing in detail an example of the supporting portion (region 58 in FIG. 5 (b)) when an oil damper is used as the damping means 54 in the device 5 of FIG. In the figure, an oil damper 60 corresponding to a damping means is provided coaxially with a coil spring 53, and has a piston 61, a cylinder 62, and a cylinder 6
2 is composed of an oil 63 filled therein. In this oil damper 60, the outer box 12 and the back plate 15
Are provided with convex portions 64 and 65, respectively. Correspondingly, concave portions 66 and 67 are formed on the outer box 12 and the back plate 15 side, respectively, and are fitted with the convex portions 64 and 65 of the oil damper 60 at these portions. Thus, the oil damper 60 functions to efficiently absorb vibration and impact energy applied to the vacuum container panel 11.

In the image forming apparatus 5 of the second embodiment having the above-described configuration, the coil spring 53 supports the vacuum container panel 11 in the vertical direction. The coil spring 53 absorbs shocks and vibrations applied from the outside together with the damping means 54, for example, the oil damper 60, so that the members constituting the vacuum vessel panel, in particular, the electron source, the back plate 15 on which the electron source is mounted, and the image display The stress applied to the front plate 14 and the like is significantly reduced. As a result, destruction of the image forming apparatus 5 is prevented, and its durability is improved.

In the image forming apparatus 5 according to the second embodiment, as shown in FIGS.
Is provided coaxially with the elastic support member 13 (coil spring 53), but the position of the damping means 54 is not particularly limited as long as it is in parallel with the elastic support member 13. As a modified example of the image forming apparatus 5 of the second embodiment, an example in which the elastic support member 13 is provided at a position other than coaxially with the damping means 54,
FIGS. 7A (plan view) and (b) (cross-sectional view along the line DD ′ in FIG. 7A).

FIG. 8 is a diagram schematically showing the configuration of the image forming apparatus of the reference example. FIG. 2A is a plan view of the device, FIG. 2B is a cross-sectional view, and FIG.
It is a top view in F 'line, (b) is EE' of (a).
It is a staircase sectional view along a line. In these drawings, members having the same functions as those of the apparatus in FIG. 1 are denoted by the same reference numerals.

In the image forming apparatus 8 shown in FIG. 8, the vacuum vessel panel 11 is accommodated in the outer box 12 while being supported by the elastic support member 83. Are different in the supporting form of the vacuum container panel. The elastic support member 83 has one end inserted and fixed in a hole formed in the back plate 15 and the other end inserted and fixed in a hole formed in the outer box 12 at a plurality of points on the periphery of the back plate 15. In this state, the vacuum vessel panel 11 is elastically supported.

In the reference example, as the elastic support member 83, for example, a rubber material or a spring structure can be used as in the first embodiment. When a rubber material is used, the shape of the member is not particularly limited, and can be appropriately selected according to the weight of the vacuum vessel panel, the use condition, the ease of production, and the like. Further, in this case, a metal casting or the like may be inserted into the member as necessary. When a spring structure is used, damping means can be used together as in the second embodiment.

In the image forming apparatus 8 of the reference example having the above configuration, when an external impact or vibration is applied,
These are absorbed by the elastic support member 83, and the stress applied to the members constituting the vacuum vessel panel 11, particularly the electron source, the back plate 15 on which the electron source is mounted, the front plate 14 for displaying an image, and the like are significantly reduced. As a result, destruction of the image forming apparatus 5 is prevented, and its durability is improved. In particular, according to the present embodiment, it is possible to very thin thickness of the device.

FIG. 9 is a diagram schematically showing the configuration of an image forming apparatus according to a fourth embodiment of the present invention. 2A is a plan view of the device, FIG. 2B is a sectional view, and FIG.
It is a top view in the HH 'line of (b), and (b) is a sectional view along the GG' line of (a). In these drawings, members having the same functions as those of the apparatus in FIG. 1 are denoted by the same reference numerals.

In the image forming apparatus 9 shown in FIG. 9, the vacuum container panel 11 has an elastic support member 13 on the non-opposing surface side of the front plate 14 and the back plate 15 in the outer box 12, as in the first embodiment. In addition to being supported by the elastic member 93, the side surface of the back plate 15 is supported by the elastic support member 93.

In this embodiment, the elastic support members 13 and 93 can be made of, for example, a rubber material or a spring structure as in the first embodiment. When a rubber material is used, the shape of the member is not particularly limited, and can be appropriately selected according to the weight of the vacuum vessel panel, the use condition, the ease of production, and the like. Further, in this case, a metal casting or the like may be inserted into the member as necessary. When a spring structure is used, damping means can be used together as in the second embodiment.

In the image forming apparatus 9 of the fourth embodiment having the above-described structure, when an external shock or vibration is applied, these are absorbed by the elastic supporting members 13 and 93, and the vacuum container panel 11 is formed. In particular, the stress applied from all directions to the members to be formed, in particular, the electron source, the back plate 15 on which the electron source is mounted, the front plate 14 for displaying images, and the like is significantly reduced. As a result, the destruction of the image forming apparatus 9 is prevented, and the durability thereof is improved.

[0049]

As described in detail above, according to the present invention,
It is possible to provide an image forming apparatus provided with a vacuum container panel on which an electron source is mounted, wherein stress applied to the vacuum container panel during transportation and use thereof is reduced as much as possible, and which has excellent durability.

[Brief description of the drawings]

FIG. 1A is a plan view illustrating a schematic configuration of an image forming apparatus according to a first embodiment of the present invention. (B): sectional view along the line AA 'in FIG.

FIG. 2 illustrates an image forming apparatus according to a first embodiment of the present invention.
Sectional drawing which shows an example of the support part of a vacuum container panel.

FIG. 3 illustrates an image forming apparatus according to a first embodiment of the present invention.
Sectional drawing which shows the other example of the support part of a vacuum container panel.

FIG. 4A is a plan view showing a schematic configuration of a surface conduction electron-emitting device used in an example of the present invention. (B): sectional view along line BB 'in FIG.

FIG. 5A is a plan view illustrating a schematic configuration of an image forming apparatus according to a second embodiment of the present invention. (B): sectional view along line CC ′ in FIG.

FIG. 6 illustrates an image forming apparatus according to a second embodiment of the present invention.
Sectional drawing which shows an example of the support part of a vacuum container panel.

FIG. 7A is a plan view illustrating a further modification of the image forming apparatus according to the second embodiment of the present invention. (B): sectional view along the line DD ′ in FIG.

8A is a plan view schematically showing the configuration of an image forming apparatus according to a reference example of the present invention, taken along line FF ′ in FIG. 8B.
(B): Step cross-sectional view along line EE 'in FIG.

FIG. 9A is a plan view schematically showing the configuration of an image forming apparatus according to a fourth embodiment of the present invention, taken along line HH ′ of FIG. 9B. (B): sectional view along line GG ′ in FIG.

[Explanation of symbols]

 1, 2, 5, 8, 9 Image forming apparatus 4 Surface conduction electron-emitting device 11 Vacuum container panel 12 Outer box 13, 83, 93 Elastic support member 14 Front plate 15 Back plate 16 Frame member 17 Support 18, 58 Support portion 21 Member made of rubber material 22, 23, 66, 67 Concave portion 24, 25, 33, 64, 65 Convex portion 32 Disc spring 41 Insulating substrate 43 Electron emitting portion 44 Thin film 45, 46 Element electrode 53 Coil spring 54 Attenuation means 60 oil damper 61 piston 62 cylinder 63 oil

Continued on the front page (72) Inventor Masahiro Tagawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Naoto Nakamura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon stock In-house (72) Inventor Hideaki Mitsutake 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yoshiyuki 3-30-2 Shimomaruko 3-chome, Ota-ku, Tokyo Canon Inc. (56 References JP-A-4-51595 (JP, A) JP-A-2-299136 (JP, A) JP-A-4-185547 (JP, A) JP-A-1-302642 (JP, A) 1-1181071 (JP, U) Japanese Utility Model 3-22951 (JP, U) Japanese Utility Model 3-63222 (JP, U) Japanese Utility Model 4-42687 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) G09F 9/00

Claims (22)

(57) [Claims] 1. An image forming apparatus comprising: a vacuum container panel having at least one or more electron sources; and a display unit that emits light when irradiated with an electron beam generated from the electron source; and an outer box that houses the vacuum container panel. a is, the vacuum container panels, within the outer box, wherein is supported by an elastic support member is interposed between the inner surface of a vacuum container panel said outer box, said vacuum container panel, on one main surface Equipped with the electron source
A back plate, and a front plate having the display means on one main surface,
Each of the main surfaces is an opposing surface, with a frame member at the peripheral edge,
In addition, at any place other than the peripheral portion,
And the frame member is sandwiched between the rear plate and the front plate.
As described above, the elastic support member is provided between the back plate and the outer box.
Between the front panel and the inner surface of the outer box.
An image forming apparatus characterized by comprising a location. 2. The image forming apparatus according to claim 1, wherein said electron source is a surface conduction electron-emitting device. 3. An image forming apparatus according to claim 1, wherein said display means is a phosphor. Wherein said elastic supporting member, the image forming apparatus according to any one of claims 1 to 3, characterized in that it consists of a rubber material. Wherein said elastic supporting member, the image forming apparatus according to any one of claims 1 to 3, characterized in that a spring structure. 6. The image forming apparatus according to claim 5 , wherein the spring structure is a disc-shaped spring. 7. The image forming apparatus according to claim 5 , wherein the spring structure is a coil spring. 8. in parallel with the spring structure, according to claim, characterized in that damping means are provided for the spring 5
8. The image forming apparatus according to any one of claims 1 to 7. 9. The image forming apparatus according to claim 8 , wherein said damping means is an air damper. 10. An image forming apparatus according to claim 8 , wherein said damping means is an oil damper. 11. The image forming apparatus according to claim 8 , wherein said attenuation means is made of a gel material based on silicone. 12. The image forming apparatus according to claim 1, wherein the elastic support member further supports the vacuum vessel panel from a side surface of the back plate. Claim 13 At least one or more electron sources and the electrons
Display means for emitting light by irradiation of an electron beam generated from a source
Vacuum container panel having a vacuum container panel
An image forming apparatus comprising: The vacuum container panel is provided with the vacuum container inside the outer box.
Elastic support member interposed between the inner panel and the inner surface of the outer box
Supported by The elastic support member is a spring structure, Reduction for the spring arranged in parallel with the spring structure
An image forming apparatus comprising a decay means. 14. The vacuum vessel panel is provided on one main surface.
A back plate on which an electron source is mounted, and the display means on one main surface.
Front plates have their main surfaces facing each other, and
Through the frame member and at any point other than the periphery.
The elastic support member is disposed to face through a pillar.
14. The support of claim 13
Image forming apparatus. 15. The electron source is a surface conduction electron-emitting device.
A child according to claim 13 or 14,
Image forming device. 16. The display means is a phosphor.
The image forming apparatus according to claim 13, wherein: 17. The elastic support member, the back plate,
Vacuum container panel so as to sandwich the frame member via a front plate
17. A support according to claim 13, wherein
Image forming device. 18. The spring structure is a disc-shaped spring.
18. The image forming apparatus according to claim 13, wherein:
Place. (19) The spring structure may be a coil spring.
Feature The image according to claims 13 to 17,
Image forming device. 20. The damping means is an air damper.
20. An image forming apparatus according to claim 13, wherein:
apparatus. 21. The damping means is an oil damper.
20. An image forming apparatus according to claim 13, wherein:
apparatus. 22. The damping means is a silicone-based
3. The method according to claim 1, wherein the material is a gel-like material.
10. The image forming apparatus according to 9.