公开(公告)号：US20160098003A1

公开(公告)日：2016-04-07

申请号：US14966911

申请日：2015-12-11

申请人： Takeshi UCHITANI ,  Masahiko SATOH ,  Kenji ISHII ,  Tadashi OGAWA ,  Teppei KAWATA ,  Arinobu YOSHIURA ,  Toshihiko SHIMOKAWA ,  Kensuke YAMAJI ,  Takamasa HASE ,  Shuutaroh YUASA ,  Masaaki YOSHIKAWA ,  Hiromasa TAKAGI ,  Takahiro IMADA ,  Hajime GOTOH ,  Akira SUZUKI ,  Takuya SESHITA ,  Hiroshi YOSHINAGA ,  Kazuya SAITO ,  Shinichi NAMEKATA ,  Takayuki SEKI ,  Yuji ARAI ,  Ryuuichi MIMBU ,  Yoshiki YAMAGUCHI ,  Shuntaroh TAMAKI ,  Yutaka IKEBUCHI

发明人： Takeshi UCHITANI ,  Masahiko SATOH ,  Kenji ISHII ,  Tadashi OGAWA ,  Teppei KAWATA ,  Arinobu YOSHIURA ,  Toshihiko SHIMOKAWA ,  Kensuke YAMAJI ,  Takamasa HASE ,  Shuutaroh YUASA ,  Masaaki YOSHIKAWA ,  Hiromasa TAKAGI ,  Takahiro IMADA ,  Hajime GOTOH ,  Akira SUZUKI ,  Takuya SESHITA ,  Hiroshi YOSHINAGA ,  Kazuya SAITO ,  Shinichi NAMEKATA ,  Takayuki SEKI ,  Yuji ARAI ,  Ryuuichi MIMBU ,  Yoshiki YAMAGUCHI ,  Shuntaroh TAMAKI ,  Yutaka IKEBUCHI

IPC分类号： G03G15/20

CPC分类号： G03G15/2064 ,  G03G15/2039 ,  G03G15/205 ,  G03G2215/2035

摘要： A fixing device includes a heat source; a fixing member looped into a generally cylindrical shape to rotate in a circumferential direction thereof and partially heated by the heat source and to heat a surface of a recording medium bearing an unfixed toner image to fix the unfixed toner image thereon in a fixing process; a rotary pressing member disposed facing the fixing member to form a nip therebetween, through which the recording medium is transported in a transport direction; and a rotation driver to rotate one of the fixing member and the pressing member. In a case in which the fixing member is halted for a reason other than the fixing process while power of the fixing device is on, electric power is not supplied to the heat source and the fixing member is rotated by a predetermined amount or more after the fixing member is halted.

公开(公告)号：US20170277091A1

公开(公告)日：2017-09-28

申请号：US15618819

申请日：2017-06-09

申请人： Takeshi UCHITANI ,  Masahiko SATOH ,  Kenji ISHII ,  Tadashi OGAWA ,  Teppei KAWATA ,  Arinobu YOSHIURA ,  Toshihiko SHIMOKAWA ,  Kensuke YAMAJI ,  Takamasa HASE ,  Shuutaroh YUASA ,  Masaaki YOSHIKAWA ,  Hiromasa TAKAGI ,  Takahiro IMADA ,  Hajime GOTOH ,  Akira SUZUKI ,  Takuya SESHITA ,  Hiroshi YOSHINAGA ,  Kazuya SAITO ,  Shinichi NAMEKATA ,  Takayuki SEKI ,  Yuji ARAI ,  Ryuuichi MIMBU ,  Yoshiki YAMAGUCHI ,  Shuntaroh TAMAKI ,  Yutaka IKEBUCHI

发明人： Takeshi UCHITANI ,  Masahiko SATOH ,  Kenji ISHII ,  Tadashi OGAWA ,  Teppei KAWATA ,  Arinobu YOSHIURA ,  Toshihiko SHIMOKAWA ,  Kensuke YAMAJI ,  Takamasa HASE ,  Shuutaroh YUASA ,  Masaaki YOSHIKAWA ,  Hiromasa TAKAGI ,  Takahiro IMADA ,  Hajime GOTOH ,  Akira SUZUKI ,  Takuya SESHITA ,  Hiroshi YOSHINAGA ,  Kazuya SAITO ,  Shinichi NAMEKATA ,  Takayuki SEKI ,  Yuji ARAI ,  Ryuuichi MIMBU ,  Yoshiki YAMAGUCHI ,  Shuntaroh TAMAKI ,  Yutaka IKEBUCHI

IPC分类号： G03G15/20

CPC分类号： G03G15/2064 ,  G03G15/2039 ,  G03G15/205 ,  G03G2215/2035

摘要： A fixing device includes a heat source; a fixing member looped into a generally cylindrical shape to rotate in a circumferential direction thereof and partially heated by the heat source and to heat a surface of a recording medium bearing an unfixed toner image to fix the unfixed toner image thereon in a fixing process; a rotary pressing member disposed facing the fixing member to form a nip therebetween, through which the recording medium is transported in a transport direction; and a rotation driver to rotate one of the fixing member and the pressing member. In a case in which the fixing member is halted for a reason other than the fixing process while power of the fixing device is on, electric power is not supplied to the heat source and the fixing member is rotated by a predetermined amount or more after the fixing member is halted.

公开(公告)号：US20150268597A1

公开(公告)日：2015-09-24

申请号：US14704389

申请日：2015-05-05

申请人： Yuji ARAI ,  Takayuki SEKI ,  Yoshiki YAMAGUCHI ,  Shuntaroh TAMAKI ,  Yutaka IKEBUCHI ,  Kazuya SAITO ,  Kenji ISHII ,  Tadashi OGAWA ,  Teppei KAWATA ,  Arinobu YOSHIURA ,  Toshihiko SHIMOKAWA ,  Kensuke YAMAJI ,  Masaaki YOSHIKAWA ,  Hiromasa TAKAGI ,  Naoki IWAYA ,  Takahiro IMADA ,  Hajime GOTOH ,  Akira SUZUKI ,  Hiroshi YOSHINAGA ,  Ryuuichi MIMBU ,  Takuya SESHITA ,  Takeshi YAMAMOTO ,  Shuutaroh YUASA

发明人： Yuji ARAI ,  Takayuki SEKI ,  Yoshiki YAMAGUCHI ,  Shuntaroh TAMAKI ,  Yutaka IKEBUCHI ,  Kazuya SAITO ,  Kenji ISHII ,  Tadashi OGAWA ,  Teppei KAWATA ,  Arinobu YOSHIURA ,  Toshihiko SHIMOKAWA ,  Kensuke YAMAJI ,  Masaaki YOSHIKAWA ,  Hiromasa TAKAGI ,  Naoki IWAYA ,  Takahiro IMADA ,  Hajime GOTOH ,  Akira SUZUKI ,  Hiroshi YOSHINAGA ,  Ryuuichi MIMBU ,  Takuya SESHITA ,  Takeshi YAMAMOTO ,  Shuutaroh YUASA

IPC分类号： G03G15/20

CPC分类号： G03G15/2017 ,  G03G15/20 ,  G03G15/2042 ,  G03G15/2053

摘要： A fixing device includes a fixing rotary body and a heater disposed opposite the fixing rotary body. A heat shield is movable in a circumferential direction of the fixing rotary body and interposed between the heater and the fixing rotary body to shield the fixing rotary body from the heater. An overheating suppressor is interposed between the heater and the heat shield to shield the heat shield from the heater. The heat shield includes an intermediate portion spanning in the circumferential direction of the fixing rotary body and movable between a shield position where the intermediate portion is disposed opposite the heater directly and a retracted position where the intermediate portion is disposed opposite the heater via the overheating suppressor.

摘要翻译： 定影装置包括固定旋转体和与定影旋转体相对设置的加热器。 隔热罩可以在固定旋转体的圆周方向上移动并插入在加热器和定影旋转体之间，以将定影旋转体屏蔽到加热器上。 过热抑制器插在加热器和隔热罩之间，以将隔热罩屏蔽到加热器上。 隔热罩包括跨过定影旋转体的圆周方向的中间部分，并且可在直接与加热器相对设置的中间部分的屏蔽位置之间移动，以及中间部分经由过热抑制器与加热器相对设置的缩回位置 。

公开(公告)号：US20150227095A1

公开(公告)日：2015-08-13

申请号：US14693550

申请日：2015-04-22

申请人： Takeshi UCHITANI ,  Masahiko SATOH ,  Masaaki YOSHIKAWA ,  Kenji ISHII ,  Tadashi OGAWA ,  Takahiro IMADA ,  Hiromasa TAKAGI ,  Hiroshi YOSHINAGA ,  Arinobu YOSHIURA ,  Teppei KAWATA ,  Takamasa HASE ,  Hajime GOTOH ,  Takuya SESHITA ,  Kazuya SAITO ,  Toshihiko SHIMOKAWA ,  Kensuke YAMAJI ,  Shuutaroh YUASA ,  Akira SUZUKI ,  Shinichi NAMEKATA ,  Ryota YAMASHINA ,  Yasunori ISHIGAYA

发明人： Takeshi UCHITANI ,  Masahiko SATOH ,  Masaaki YOSHIKAWA ,  Kenji ISHII ,  Tadashi OGAWA ,  Takahiro IMADA ,  Hiromasa TAKAGI ,  Hiroshi YOSHINAGA ,  Arinobu YOSHIURA ,  Teppei KAWATA ,  Takamasa HASE ,  Hajime GOTOH ,  Takuya SESHITA ,  Kazuya SAITO ,  Toshihiko SHIMOKAWA ,  Kensuke YAMAJI ,  Shuutaroh YUASA ,  Akira SUZUKI ,  Shinichi NAMEKATA ,  Ryota YAMASHINA ,  Yasunori ISHIGAYA

IPC分类号： G03G15/20

CPC分类号： G03G15/2039 ,  G03G15/205 ,  G03G2215/2035

摘要： A fixing device capable of shifting to a sleep state includes a heat source; a rotatable fixing member that is partly heated by the heat source to heat an unfixed image carrying surface of a recording medium; a rotatable pressing member that is in pressure contact with the fixing member to form a nip portion between the pressing member and the fixing member; a rotation drive unit that directly or indirectly rotates the fixing member; a temperature detecting unit that detects a temperature of the fixing member; and a controller configured to prohibit the fixing device from shifting to the sleep state when the temperature of the fixing member in a region facing the heat source is equal to or more than a predetermined temperature T1 at a point when a predetermined time period t1 has elapsed from the stop of rotation drive of the rotation drive unit.

摘要翻译： 能够转移到睡眠状态的固定装置包括热源; 可旋转的固定构件，其被热源部分地加热以加热记录介质的未固定的图像承载表面; 与所述固定部件压力接触以在所述按压部件和所述固定部件之间形成夹持部的旋转按压部件; 旋转驱动单元，其直接或间接地旋转所述固定构件; 温度检测单元，其检测所述固定构件的温度; 以及控制器，被配置为当经过预定时间段t1的时刻，当面向热源的区域中的固定构件的温度等于或大于预定温度T1时，禁止定影装置转移到睡眠状态 从旋转驱动单元的旋转驱动停止。

公开(公告)号：US20130209119A1

公开(公告)日：2013-08-15

申请号：US13747906

申请日：2013-01-23

申请人： Shuutaroh YUASA ,  Takeshi UCHITANI ,  Takamasa HASE ,  Takuya SESHITA ,  Hiroshi YOSHINAGA ,  Kenji ISHII ,  Tadashi OGAWA ,  Arinobu YOSHIURA ,  Teppei KAWATA ,  Toshihiko SHIMOKAWA ,  Kensuke YAMAJI ,  Masaaki YOSHIKAWA ,  Masahiko SATOH ,  Hiromasa TAKAGI ,  Takahiro IMADA ,  Hajime GOTOH ,  Akira SUZUKI ,  Shinichi NAMEKATA ,  Kazuya SAITO

发明人： Shuutaroh YUASA ,  Takeshi UCHITANI ,  Takamasa HASE ,  Takuya SESHITA ,  Hiroshi YOSHINAGA ,  Kenji ISHII ,  Tadashi OGAWA ,  Arinobu YOSHIURA ,  Teppei KAWATA ,  Toshihiko SHIMOKAWA ,  Kensuke YAMAJI ,  Masaaki YOSHIKAWA ,  Masahiko SATOH ,  Hiromasa TAKAGI ,  Takahiro IMADA ,  Hajime GOTOH ,  Akira SUZUKI ,  Shinichi NAMEKATA ,  Kazuya SAITO

IPC分类号： G03G15/20

CPC分类号： G03G15/2064 ,  G03G15/205 ,  G03G2215/2035

摘要： A fixing device includes a controller connected to a heater and at least one of a pressing rotary body and an endless rotary body. The controller performs a first fixing operation, a first transition operation, a second fixing operation, and a second transition operation. The first fixing operation fixes a toner image on a first recording medium after the fixing device is powered on. The first transition operation rotates the pressing rotary body and the endless rotary body while controlling the heater to maintain the endless rotary body at a predetermined temperature for a first duration time. The second fixing operation fixes a toner image on a second recording medium. The second transition operation rotates the pressing rotary body and the endless rotary body while controlling the heater to maintain the endless rotary body at the predetermined temperature for a second duration time smaller than the first duration time.

摘要翻译： 定影装置包括连接到加热器和压紧旋转体和环形旋转体中的至少一个的控制器。 控制器执行第一定影操作，第一转换操作，第二定影操作和第二转换操作。 第一固定操作在定影装置通电之后将调色剂图像定影在第一记录介质上。 第一过渡操作使加压旋转体和环形旋转体一起旋转，同时控制加热器，以将永久旋转体保持在预定温度下持续第一持续时间。 第二定影操作将调色剂图像固定在第二记录介质上。 第二过渡操作在控制加热器的同时使压制旋转体和环形旋转体旋转，将环形旋转体保持在预定温度下，持续时间小于第一持续时间。

公开(公告)号：US20170255150A1

公开(公告)日：2017-09-07

申请号：US15602720

申请日：2017-05-23

申请人： Takamasa HASE ,  Masahiko SATOH ,  Shinichi NAMEKATA ,  Kenji ISHll ,  Takeshi UCHITANI ,  Tadashi OGAWA ,  Teppei KAWATA ,  Arinobu YOSHIURA ,  Kazuya SAITO ,  Toshihiko SHIMOKAWA ,  Shuutaroh YUASA ,  Kensuke YAMAJI ,  Masaaki YOSHIKAWA ,  Hiroshi YOSHINAGA ,  Hiromasa TAKAGI ,  Naoki IWAYA ,  Takuya SESHITA ,  Takahiro IMADA ,  Hajime GOTOH ,  Akira SUZUKI

发明人： Takamasa HASE ,  Masahiko SATOH ,  Shinichi NAMEKATA ,  Kenji ISHll ,  Takeshi UCHITANI ,  Tadashi OGAWA ,  Teppei KAWATA ,  Arinobu YOSHIURA ,  Kazuya SAITO ,  Toshihiko SHIMOKAWA ,  Shuutaroh YUASA ,  Kensuke YAMAJI ,  Masaaki YOSHIKAWA ,  Hiroshi YOSHINAGA ,  Hiromasa TAKAGI ,  Naoki IWAYA ,  Takuya SESHITA ,  Takahiro IMADA ,  Hajime GOTOH ,  Akira SUZUKI

IPC分类号： G03G15/20 ,  G03G15/00

CPC分类号： G03G15/2028 ,  G03G15/2039 ,  G03G15/205 ,  G03G15/55

摘要： An image forming apparatus includes a fixing device. The fixing device includes a rotatable endless fixing member, a nip forming member arranged inside the fixing member, a pressing member in contact with the nip forming member via the fixing member, and a heating source configured to heat the fixing member. When an abnormality occurs in at least one of the fixing device and other devices included in the image forming apparatus, a rotation of the fixing member is stopped prior to stopping a rotation driving of a discharging unit and, after stopping, the fixing member is controlled to rotate.

公开(公告)号：US20160054691A1

公开(公告)日：2016-02-25

申请号：US14928757

申请日：2015-10-30

申请人： Takamasa HASE ,  Masahiko SATOH ,  Shinichi NAMEKATA ,  Kenji ISHll ,  Takeshi UCHITANI ,  Tadashi OGAWA ,  Teppei KAWATA ,  Arinobu YOSHIURA ,  Kazuya SAITO ,  Toshihiko SHIMOKAWA ,  Shuutaroh YUASA ,  Kensuke YAMAJI ,  Masaaki YOSHIKAWA ,  Hiroshi YOSHINAGA ,  Hiromasa TAKAGI ,  Naoki IWAYA ,  Takuya SESHITA ,  Takahiro IMADA ,  Hajime GOTOH ,  Akira SUZUKI

发明人： Takamasa HASE ,  Masahiko SATOH ,  Shinichi NAMEKATA ,  Kenji ISHll ,  Takeshi UCHITANI ,  Tadashi OGAWA ,  Teppei KAWATA ,  Arinobu YOSHIURA ,  Kazuya SAITO ,  Toshihiko SHIMOKAWA ,  Shuutaroh YUASA ,  Kensuke YAMAJI ,  Masaaki YOSHIKAWA ,  Hiroshi YOSHINAGA ,  Hiromasa TAKAGI ,  Naoki IWAYA ,  Takuya SESHITA ,  Takahiro IMADA ,  Hajime GOTOH ,  Akira SUZUKI

IPC分类号： G03G15/20

CPC分类号： G03G15/2028 ,  G03G15/2039 ,  G03G15/205 ,  G03G15/55

摘要： An image forming apparatus includes a fixing device. The fixing device includes a rotatable endless fixing member, a nip forming member arranged inside the fixing member, a pressing member in contact with the nip forming member via the fixing member, and a heating source configured to heat the fixing member. When an abnormality occurs in at least one of the fixing device and other devices included in the image forming apparatus, a rotation of the fixing member is stopped prior to stopping a rotation driving of a discharging unit and, after stopping, the fixing member is controlled to rotate.

公开(公告)号：US20130209125A1

公开(公告)日：2013-08-15

申请号：US13751922

申请日：2013-01-28

申请人： Takeshi UCHITANI ,  Masahiko SATOH ,  Masaaki YOSHIKAWA ,  Kenji ISHII ,  Tadashi OGAWA ,  Takahiro IMADA ,  Hiromasa TAKAGI ,  Kazuya SAITO ,  Naoki IWAYA ,  Toshihiko SHIMOKAWA ,  Kensuke YAMAJI ,  Teppei KAWATA ,  Takamasa HASE ,  Takuya SESHITA ,  Shuutaroh YUASA ,  Arinobu YOSHIURA ,  Hajime GOTOH ,  Akira SUZUKI ,  Hiroshi YOSHINAGA

发明人： Takeshi UCHITANI ,  Masahiko SATOH ,  Masaaki YOSHIKAWA ,  Kenji ISHII ,  Tadashi OGAWA ,  Takahiro IMADA ,  Hiromasa TAKAGI ,  Kazuya SAITO ,  Naoki IWAYA ,  Toshihiko SHIMOKAWA ,  Kensuke YAMAJI ,  Teppei KAWATA ,  Takamasa HASE ,  Takuya SESHITA ,  Shuutaroh YUASA ,  Arinobu YOSHIURA ,  Hajime GOTOH ,  Akira SUZUKI ,  Hiroshi YOSHINAGA

IPC分类号： G03G15/20

CPC分类号： G03G15/2078 ,  G03G15/2039 ,  G03G15/2042 ,  G03G2215/2035

摘要： A fixing device for fixing an unfixed image onto a recording medium includes a fixing belt, a nip forming member, an opposing rotary member, a heater, and a temperature detector. The fixing belt is formed into a loop to move endlessly and fix the unfixed image on the recording medium. The nip forming member is disposed inside the loop formed by the fixing belt. The opposing rotary member contacts the nip forming member via the fixing belt to form a nip portion therebetween while rotating. The heater heats the fixing belt at a place other than the nip portion. The temperature detector detects a temperature of the surface of the fixing belt. The temperature detector detects the temperature near a place of the fixing belt that easily deforms as the fixing belt is heated by the heater.

摘要翻译： 用于将未定影图像固定到记录介质上的定影装置包括定影带，辊隙形成构件，相对旋转构件，加热器和温度检测器。 将定影带形成为环状以循环移动并将未定影图像固定在记录介质上。 辊隙形成构件设置在由定影带形成的环内。 相对的旋转构件经由定影带与辊隙形成构件接触，在旋转的同时在其间形成夹持部。 加热器将定影带加热到夹持部以外的位置。 温度检测器检测定影带的表面的温度。 温度检测器检测定影带靠近加热器加热定影带时容易变形的位置附近的温度。

公开(公告)号：US20150212459A1

公开(公告)日：2015-07-30

申请号：US14682509

申请日：2015-04-09

申请人： Takamasa HASE ,  Masahiko SATOH ,  Masaaki YOSHIKAWA ,  Kenji ISHII ,  Hiroshi YOSHINAGA ,  Tadashi OGAWA ,  Takeshi UCHITANI ,  Hiromasa TAKAGI ,  Naoki IWAYA ,  Teppei KAWATA ,  Takuya SESHITA ,  Arinobu YOSHIURA ,  Takahiro IMADA ,  Hajime GOTOH ,  Kazuya SAITO ,  Toshihiko SHIMOKAWA ,  Shuutaroh YUASA ,  Kensuke YAMAJI ,  Akira SUZUKI

发明人： Takamasa HASE ,  Masahiko SATOH ,  Masaaki YOSHIKAWA ,  Kenji ISHII ,  Hiroshi YOSHINAGA ,  Tadashi OGAWA ,  Takeshi UCHITANI ,  Hiromasa TAKAGI ,  Naoki IWAYA ,  Teppei KAWATA ,  Takuya SESHITA ,  Arinobu YOSHIURA ,  Takahiro IMADA ,  Hajime GOTOH ,  Kazuya SAITO ,  Toshihiko SHIMOKAWA ,  Shuutaroh YUASA ,  Kensuke YAMAJI ,  Akira SUZUKI

IPC分类号： G03G15/20

CPC分类号： G03G15/205 ,  G03G15/2039 ,  G03G2215/2035

摘要： A fixing device including a fixing member, an opposing member, a plurality of heat sources, and a voltage detector. The opposing member is disposed opposite the fixing member to contact the fixing member to form a nip portion at which an unfixed image on a recording medium is fixed. The plurality of heat sources heats the fixing member. The voltage detector detects an applied voltage of at least one of the plurality of heat sources. Upon detection of the applied voltage of the heat sources by the voltage detector, a voltage is applied to at least one of the heat sources.

摘要翻译： 一种固定装置，包括固定构件，相对构件，多个热源和电压检测器。 相对构件与固定构件相对地设置以接触固定构件，以形成固定有记录介质上的未定影图像的夹持部。 多个热源加热固定部件。 电压检测器检测多个热源中的至少一个的施加电压。 在通过电压检测器检测到热源的施加电压时，向至少一个热源施加电压。

公开(公告)号：US20130202320A1

公开(公告)日：2013-08-08

申请号：US13744883

申请日：2013-01-18

申请人： Takamasa HASE ,  Masahiko SATOH ,  Masaaki YOSHIKAWA ,  Kenji ISHII ,  Hiroshi YOSHINAGA ,  Tadashi OGAWA ,  Takeshi UCHITANI ,  Hiromasa TAKAGI ,  Naoki IWAYA ,  Teppei KAWATA ,  Takuya SESHITA ,  Arinobu YOSHIURA ,  Takahiro IMADA ,  Hajime GOTOH ,  Kazuya SAITO ,  Toshihiko SHIMOKAWA ,  Shuutaroh YUASA ,  Kensuke YAMAJI ,  Akira SUZUKI

发明人： Takamasa HASE ,  Masahiko SATOH ,  Masaaki YOSHIKAWA ,  Kenji ISHII ,  Hiroshi YOSHINAGA ,  Tadashi OGAWA ,  Takeshi UCHITANI ,  Hiromasa TAKAGI ,  Naoki IWAYA ,  Teppei KAWATA ,  Takuya SESHITA ,  Arinobu YOSHIURA ,  Takahiro IMADA ,  Hajime GOTOH ,  Kazuya SAITO ,  Toshihiko SHIMOKAWA ,  Shuutaroh YUASA ,  Kensuke YAMAJI ,  Akira SUZUKI

IPC分类号： G03G15/00 ,  G03G15/20

CPC分类号： G03G15/205 ,  G03G15/2039 ,  G03G2215/2035

摘要： A fixing device including a fixing member, an opposing member, a plurality of heat sources, and a voltage detector. The opposing member is disposed opposite the fixing member to contact the fixing member to form a nip portion at which an unfixed image on a recording medium is fixed. The plurality of heat sources heats the fixing member. The voltage detector detects an applied voltage of at least one of the plurality of heat sources. Upon detection of the applied voltage of the heat sources by the voltage detector, a voltage is applied to at least one of the heat sources.